The number of protons equals
The number of electrons
The number of neutrons
Limestone is mainly
Sodium carbonate
Calcium carbonate
Magnesium carbonate
Metals are: Choose 3
Good conductors of electricity
Colourful when molten
Strong
Good conductors of heat
Alloys are softer than pure metals
Crude oil is mainly made up of hydrocarbon molecules
Sulphur dioxide causes acid rain
Cracking means splitting up long- chain hydrocarbons
Polymers are: Choose 3
Cheap
Expensive
Most aren't biodegradable
Biodegradable
Most don't rot
Choose every right answer about vegetable oils (3)
Have benefits for cooking
Used in detergents
Used to produce fuels
Used in food
Unsaturated oils contain double bonds
Hydrophilic ends of an emulsifier latch onto oil molecules
Why wasn't Wegner's theory of continental drift accepted for many years? Choose 2
He had got his facts mixed up
He had used inaccurate data in his calculations
Many believed it to be impossible
he was ahead of his time
The centre of the Earth is mainly made of iron and nickel
The early atmosphere was mainly
methane
oxygen
carbon dioxide
nitrogen
Ethanol can be produced from plant materials
Biodiesel can be produced from vegetable oils
The mass number is the total number of protons and electrons
The atomic number tells you the number of protons or electrons
Emulsifiers stop emulsions from seperating out and this gives them a longer shelf life. They allow food companies to produce food lower in fat
No one is known to be allergic to emulsifiers so they can be very useful
Convection currents in the mantle cause plates to drift
The oceans formed when the water vapour condensed
the oceans are a natural store of carbon dioxide, however the amount of CO2 we're releasing is making them too acidic
Polymers are: Choose 2
Very durable
Now mostly having waterproof coating
Very strong
Light,stretchable
Saturated fats are healthier than unsaturated fats
