CHEMISTRY 1
Name three properties of metals.
malleable, lustrous, conductor of heat and electricity, reacts with acid, hard and dense
How many electrons can fit into each shell?
2 in the first, 8 in the rest
What type of force leads to static electricity and why?
friction can rip off electrons
Name three things we cannot do without fossil fuels.
see at night, operate phones/TV/computers, drive cars/buses/trains, cannot take hot showers or cook food
Name three non-renewable resources.
hydro, solar, wind, biomass and geothermal
Explain the difference between an element, compound and mixture.
element = only contains one type of atom, compound = contains atoms from different elements chemically bonded together, mixture = elements and compounds are mixed together but not chemically bonded
Explain why rusting is a chemical change but heating metal is a physical change.
rusting = colour change, formation of a new substance, disappearance of a reactant, heating = physical because it may melt but it is still metal and has only changed in state
Explain how an electromagnet works.
when electricity is passed through the copper wire, it turns the nail into a magnet because the magnetic field has been strengthened
Explain the difference between current and voltage.
current = flow of electrons, voltage = push of electrons
Name three fossil fossils.
coal, oil and gas
How do you calculate the number of electrons, protons and neutrons in an atom?
electrons and protons are the atomic number, neutrons = mass number - atomic number
Why is an atom always neutral?
they have equal numbers of protons and neutrons
Compare a circuit to a water fountain.
current = amount of water, voltage = pressure, resistance = how large/long the pipes are
How is current and voltage measured in a circuit?
current = ammeter in series, voltage = voltmeter in parallel
Draw a Sankey diagram for an electric drill which has an input energy of 500J and an output energy of 350J.
should include 500J on left, and 350 +150J on right
Draw the atomic structure of sodium.
electrons = 11, protons = 11, neutrons = 23
nucleus = protons and neutrons, correct number of electrons in electron shells
Explain why a compound is also a molecule.
a molecule is 2+ atoms bonded together but a compound must contains atoms of different elements
Explain how electricity is produced from coal.
coal is burned to heat water, steam turns a turbine which spins a generator, the generator contains an electromagnet which produces electricity
Explain why parallel circuits are used at home and in buildings.
in a series circuit, if one component is broken the whole circuit will not work - this is not the case for parallel circuits
Calculate the energy efficiency of a light bulb which has an input energy of 240J and an output energy of 100J.
100/240 x 100 = 42%
Draw/Explain Rutherford's model of the atom.
mostly empty space with positive nucleus
Draw/Explain JJ Thomson's model of the atom.
plum pudding
Explain how Benjamin Franklin discovered electricity.
he flew a kite during a thunderstorm and was electrocuted = static electricity
Explain 3 ways resistance in a circuit can be increased.
increasing the length of wire, thinner wire, resistant material e.g. placing an insulator
Explain how carbon dioxide can lead to acid rain which is damaging for the environment.
carbon dioxide and water reacts to make carbonic acid = corrosive