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Hint
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Answer
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Elements are made up of ___ type of atom
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One
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Compounds are formed when different elements are ___ ___ in fixed proportions
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Chemically bonded
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Mixtures are two or more elements and/or compounds not chemically bonded. Chemical properties of each element are ___.
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Unchanged
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Separation of insoluble solids from liquids is done by ___
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Filtration
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Pour mixture into funnel. Insoluble solids remain in the ___ ___ and liquids pass through into flask
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Filter paper
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Separation of a solid dissolved in water is done by ___
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Crystallisation
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Heat in evaporating dish to ___ the solution. Leave in warm place to allow remaining water to evaporate.
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Concentrate
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To see what kind of different substances are in a mixture, eg. ink, you use ___ ___
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Paper chromatography
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Draw a ___ ___ near the bottom of the paper, add spots of colouring
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Pencil line
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Put paper into a chromatography tank with solvent ___ the line
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Below
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Dyes carried up by paper at different ___ and you can calculate their Rf value to identify them
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Rates
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Rf = distance moved by ___/distance moved by ___ (answer as __, __)
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Substance, solvent
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To separate a mixture of two liquids or a solution of a solid in water
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Simple distillation
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In a mixture of two liquids, the one with the lower boiling point is collected as the ___
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Distillate
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In a solution of a solid in water, the ___ is collected
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Water
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A ___ is used to condense the gases into liquids when they have evaporated (has two tubes, one inside other, and cooling water runs through space in between.)
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Condenser
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To separate a mixture of more than two liquids
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Fractional distillation
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___ ___ is packed with glass beads
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Fractionating column
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Different liquids leave the top of the column in order of ___ boiling point
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Increasing
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___ originally thought atoms were tiny spheres that could not be made smaller
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Democritus
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___ were the first subatomic particles discovered
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Electrons
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The ___ ___ model illustrated a positively charged "pudding" studded with electrons. JJ Thomson
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Plum pudding
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Rutherford's ___ ___ ___ experiment showed most positive particles fired at an atom went straight through, suggesting that most of an atom is empty space.
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Alpha particle scattering
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___ model showed small positively charged sphere with a nucleus and empty space.
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Nuclear
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___'s model showed electrons orbiting the nucleus at a specific distance, and the discovery of protons supported this.
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Bohr
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About 20 years after the nucleus was accepted, ___ discovered neutrons.
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Chadwick
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Number of protons in one atom of an element (same as number of electrons as atoms have no overall charge)
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Atomic number
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Total number of protons and neutrons in an atom
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Mass number
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Atoms of the same element that have different numbers of neutrons
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Isotopes
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The mean value of atomic masses of these is the relative atomic mass and is calculated proportionally to the ___ of these (above).
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Abundance
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Electrons in elements occupy the ___ possible energy level.
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Lowest
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Dmitri Mendeleev's periodic table improved early versions because it left gaps for ___ ___
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Undiscovered elements
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This meant that similar elements lined up in ___
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Groups
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Nowadays, the periodic table is sorted by ___ ___
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Atomic number
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Electrons in the same group have similar properties and the same number of ___ ___
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Outer electrons
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Have few electrons in outer shell, lose electrons to form positive ions in ionic compounds
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Metals
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All of these except ___ are solids at room temperature. All conduct electricity.
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Mercury
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Are few electrons short of full outer shell. Gain electrons to form negative ions in ionic compounds or share electrons in covalent compounds.
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Non metals
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Some have ___ structures and are solids at room temperature with a high melting point.
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Giant
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Some are ___ ___ and are gases, liquids or solids at room temperature with a low melting point.
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Simple molecules
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They do not conduct electricity, except some forms of ___
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Carbon
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Outer shell of this group is full. Stable arrangement means atoms do not easily form molecules and are inert.
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0
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This group is the alkali metals. Low density - first three are less dense than water.
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1
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Reacts to form ions with ___ charge.
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+1
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React with ___ to form hydroxides and hydrogen.
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Water
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React with ___ to form solid, white ionic oxides
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Oxygen
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React with ___ to form solid, white ionic chlorides
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Halogens
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Going ___ the group, reactivity increases
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Down
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This group is the halogens. Non-metals consisting of molecules with pairs of atoms.
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7
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React with metals to form ionic compounds, forming halide ions with a charge of ___
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-1
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React with other non-metals to form simple molecular ___ ___
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Covalent compounds
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Going ___ the group, reactivity increases
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Up
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A more reactive halogen can ___ a less reactive halogen from an aqueous solution of its salt.
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Displace
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___ metals, compared to the alkali metals, are higher density, stronger, harder, have higher melting/boiling points
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Transition
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They are much ___ reactive with water, oxygen and halogens
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Less
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Many also form coloured compounds, are useful ___ and form more than one type of ion
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Catalysts
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Bonds formed when metals react with non-metals. Atoms of metal transfer outer electrons to non-metal atoms. Oppositely charged ions with full outer shells. Strong bond between ions.
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Ionic
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In a compound, strong electrostatic attraction between oppositely charged ions forms a ___ ___ structure.
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Giant lattice
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Metallic bonding: In metal elements and alloys, outer electrons of atoms are ___
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Delocalised
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This leaves a ___ of metal ions
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Lattice
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Electrostatic attraction between metal ions and electrons makes a ___ metallic bond.
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Strong
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Pure metals are too soft to use for many purposes, so other metals are mixed in to make ___ that are harder.
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Alloys
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These distort the ___ ___ ___, so layers cannot slide as easily as in a pure metal.
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Layers of ions
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Bonds formed when non-metal atoms bond to other non-metal atoms
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Covalent
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The bonds are strong but the ___ ___ are not
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Intermolecular forces
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___ ___ have a low melting and boiling point due to weak (above)
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Small molecules
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Some compounds with atoms that are joined up by covalent bonds form very large molecules, made of repeating units - ___
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Polymers
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Forces between molecules are relatively strong compared with other covalent molecules so they are ___ at room temperature.
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Solid
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Form of carbon with giant covalent structure.
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Diamond
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Each atom bonds to 4 others to form a lattice with a ___ structure.
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Tetrahedral
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Very ___ and does not conduct electricity. High melting point.
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Hard
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Form of carbon where carbon atoms form layers with weak intermolecular forces between them
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Graphite
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It's soft and ___, conducts electricity and has a high melting point.
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Slippery
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Single layer of ^^^ one atom thick.
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Graphene
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It's a ___conductor so is useful in electronics.
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Semi
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Molecules of carbon atoms with spherical or otherwise hollow structures
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Fullerene
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Based off ___ of carbon, may also have five-carbon and seven-carbon rings.
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Hexagons
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Include ___, C60, which is spherical.
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Buckminsterfullerene
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Used in medicines to contain and deliver drugs, as a ___, or as a surface for a catalyst.
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Lubricant
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Cylindrical fullerenes which are very ___ compared to their diameter.
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Long
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High ___ ___. Good conductors.
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Tensile strength
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Used in electronics, ____, or reinforcing materials (such as the frame of a tennis racket.)
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Nanotechnology
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Particle Theory: When solid substance is ___, particles gain energy.
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Heated
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When they have sufficient energy to overcome the forces between them, the substance ___
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Melts
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If further heated, the substance ___ when particles have sufficient energy to overcome forces between them again
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Boils
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Stronger forces between particles = ___ melting/boiling points
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Higher
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Limitations of the model: particles in real substances aren't often ___ and the model does not show forces between particles.
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Spheres
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___ relates to structures with a few hundred atoms - nanoparticles.
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Nanoscience
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These, and atoms, have properties different to the same material in bulk due to a high ___ ___ compared to volume
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Surface area
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Can be used in medicine to deliver drugs, as synthetic skin, in electronics, cosmetics, suncreams, in deoderants, and as catalysts in ___ ___ (due to large SA)
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Fuel cells
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Avogadro's constant = ___ x 10^23
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6.02
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One mole of any substance contains ___ ___ number of particles.
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The same
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Mol = ___ / Mr
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Mass
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The ___ ___ ___ of a substance in grams is known as one mole of that substance.
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Relative formula mass
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Titrations RP: Wear eye protection. Rise a ___ and fill with NaOH solution.
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Burette
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Rinse a ___ and then use it to add 25.0cm^3 dilute HCl to a conical flask.
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Pipette
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Add a few drops of ___ and swirl.
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Phenolphthalein
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Add alkali slowly, swirling the flask. Take a ___ titration when the indicator changes colour
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Rough
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Repeat until you have 3 values that are within 0.10 cm^3 of each other - ___ results. Do this by adding the alkali in drops when close to the end point.
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Precise
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Concentration = Amount (in mol or g) / ___
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Volume
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In reactions with gases, calculate the number of moles and then multiply by ___ to find gas volume
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24
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Equal numbers of moles of any gas have the same volume at the same ___ and pressure
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Temperature
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Amount of product obtained in a chemical reaction
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Yield
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Maximum yield that can be obtained from a chemical reaction
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Theoretical yield
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Actual yield is less than this. Some product lost while separating from reaction mixture, reactants may produce by-___, reaction may be reversible so not go to completion.
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Products
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Mass of moles of desired product/mass of moles of all reactants = ___
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Atom economy
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Reactivity series order (type in with no commas)
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Potassium sodium calcium magnesium aluminium carbon zinc iron tin lead hydrogen copper silver gold
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Mnemonic for this order (type in with no commas)
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Please stop calling me a careless zebra instead try learning how copper saves gold
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From potassium to aluminium, a ___, decreasing in speed, is seen when reacting with water.
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Fizzing
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From ___ down, no observable reaction.
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Zinc
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They form a ___ ___ and hydrogen gas.
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Metal hydroxide
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With acid, vigorous fizzing down to ___.
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Aluminium
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___ and iron see slow fizzing. There's no observable reaction in copper, silver or gold.
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Zinc
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React with acids to form a ___ ___ and hydrogen.
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Metal salt
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A more reactive metal will ___ a less reactive metal from its compound.
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Displace
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Metals above ___ in the reactivity series will displace it from acids.
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Hydrogen
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___ can replace metals less reactive than itself from their compounds.
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Carbon
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Loss of electrons.
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Oxidation
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Many metals react with oxygen from the air to form ___ ___
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Metal oxides
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Gain of electrons.
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Reduction
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Unreactive metals are found as their ___
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Ore
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Metals less reactive than carbon can be extracted from their oxides by ___ with carbon
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Heating
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Those more reactive than carbon require ___
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Electrolysis
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Bases include ___ (soluble metal hydroxides), insoluble metal hydroxides, and insoluble metal oxides.
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Alkali
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Metal + acid -> ___ ___ + hydrogen
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Metal salt
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Acid + base -> ___ + water
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Salt
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Acid + ___ ___ -> salt + water + carbon dioxide
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Metal carbonate
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RP Salt Preparation: Measure 50cm^3 dilute acid into a beaker, and gently ___.
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Heat
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Using a ___, add metal oxide and stir with glass rod.
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Spatula
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Wait until all has reacted, then add a further sample. Repeat till there's an ___ of oxide.
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Excess
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___ into another beaker.
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Filter
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Transfer to an ___ ___ and heat until half the water has evaporated to concentrate the solution.
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Evaporating dish
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Leave in a warm place until ___ have formed
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Crystals
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Scrape onto filter paper and ___ ___
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Pat dry
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pH scale is measured from 0 to ___
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14
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A ___ pH means the substance is more acidic.
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Lower
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pH___ is neutral
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7
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As a solution becomes more acidic, ___ ion concentration increases
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Hydrogen
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As it becomes more alkaline, ___ concentration increases
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Hydroxide
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Strong acids are ___ ionised into hydrogen. Include hydrochloric, nitric, sulfuric.
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Fully
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Weak acids are ___ ionised. Include carbonic, ethanoic.
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Partially
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The decomposition of an ionic compound when melted or dissolved, using electricity
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Electrolysis
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In a solid, ions are held firmly in a lattice so solid ionic compounds don't ___ ___
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Conduct electricity
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When melted/dissolved in water, the ions are released and can move and carry ___, therefore are conductors
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Current
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As electrolysis occurs, positive ions move to the negative electrode (___)
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Cathode
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Negative ions move to the positive one (___)
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Anode
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We need aluminium as it's low density and strong when ___
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Alloyed
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A molten mixture is made of aluminium oxide and ___ to lower the melting point
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Cryolite
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The mixture is put into a tank. At the carbon anode, ___ is formed
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Oxygen
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This produces ___ ___ when reacting with the electrode
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Carbon dioxide
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At the cathode, aluminium ions are ___, producing pure alumium
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Reduced
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Electrolysis is ___ because of the energy required to melt compounds and produce currents
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Expensive
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If the metal in the substance being electrolysed is ___ reactive than hydrogen, hydrogen is produced at the cathode. If not, the metal is.
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More
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If the electrolysed substance contains halide ions, the halogen is produced at the anode. If not, ___ is produced.
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Oxygen
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RP: Set up two carbon electrodes in a beaker, with a soluble substance dissolved in water for the ___.
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Electrolyte
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Turn on ___ supply.
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dc
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At the cathode, either hydrogen will produce a colourless gas, or ___ will produce a red-brown solid.
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Copper
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At the anode, oxygen will produce a colourless gas, bromine an ___ ___, or chlorine a pale green gas.
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Orange solution
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Energy required to break bonds is less than energy given out when making bonds
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Exothermic
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Includes combustion, oxidation, and ___.
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Neutralisation
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Energy of products is ___ than the energy of the reactants.
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Less
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Energy required to break bonds is more than energy given out when making bonds
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Endothermic
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Includes thermal decomposition, and the reaction of ___ ___ with sodium hydrogen carbonate
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Citric acid
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Energy of products is ___ than the energy of reactants
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More
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When an acid reacts with a metal, metal carbonate or alkali, the energy change of the reaction causes change in the ___ of the mixture.
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Temperature
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RP Energy Changes: Different ___ of acid give different temperature rises.
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Concentrations
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Set up a beaker in a ___ cup with a thermometer.
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Polystyrene
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Measure 50cm^3 of dilute HCl and record the initial temperature. Add ___ powder in excess.
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Zinc
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Stir with thermometer until temperature stops increasing. Record the ___ temperature.
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Maximum
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Repeat the experiment with acid and ___ mixtures
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Water
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Minimum energy needed for a reaction to occur when reactant particles collide
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Activation energy
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Energy needed to break a bond
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Bond energy
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Contain chemicals that react together to produce electricity
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Cell
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Two or more of these can be connected to form a ___ of higher voltage
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Battery
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Chemical cells are where 2 metals are connected in contact with an ___
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Electrolyte
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Portable and can be rechargeable (reaction is reversed by applying an ___ ___)
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External current
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However, difficult to dispose of, and, when one of the reactants in a ___ ___ cell runs out, chemical reactions stop.
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Non rechargeable
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Fuel cells are continuously supplied with ___ which is oxidised to provide a potential difference.
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Hydrogen
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Constant voltage and do not run down as fuel is supplied ___
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Continuously
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Only waste product is ___. However, they're not portable
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Water
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