Atomic radius decreases from left to right across the periodic table.
"A compound with the same molecular formula but a different structural formula.""A compound with a different molecular formula but the same structural formula."
In structural isomers atoms are arranged in completely different orders. You can't just twist two structural isomers in space to make them look the same again.
High temperatureHigh pressureBoth high temperature and high pressure
Thermal cracking requires temperatures in the hundreds of degrees, and tens of atmospheres of pressure.
This is in contrast to catalytic cracking, which produces It also produces high proportions of branched alkanes.
Hydrogen has one proton, helium has two, and lithium has three. You're given the mass numbers in the question, so you can work out how many neutrons each has from this information. 3H has two neutrons, 4He and 5He have two and three respectively, and 4Li has one neutron.
It has no geometric isomers because there is free rotation around the C=C bond.It burns in excess oxygen to produce carbon dioxide and water.The C=C bond is twice as strong as the C–C bond in ethane.
When there's plenty of oxygen, all hydrocarbons burn to produce carbon dioxide and water.
Reduction happens when a substance gains electrons during a chemical reaction, and oxidation is when a substance loses electrons.
A reducing agent is what gives electrons in a redox reaction. Strong reducing agents easily lose electrons.
It reacts with Tollens’ reagent to form silver.It has a higher boiling point than ethanol.Its empirical and molecular formulas are different.
Tollen's reagent determines the presence of an aldehyde.
Unburned hydrocarbonsWater vapourCarbon dioxideNitrogen
On its own, molecular nitrogen (N2) does not retain heat so is not a greenhouse gas.
1s2 2s2 2p6 3s2 3p6 3d71s2 2s2 2p6 3s2 3p6 3d7 4s2
Cobalt atoms lose their two electrons from the 4s orbital when they become a cobalt(II) ion.
AgCl dissolves to give a colourless solution when aqueous ammonia is added.
Could You Pass A-Level Chemistry Now?
Sorry, we know this quiz was difficult – but it was multiple choice. You failed.
Well, you only got three or four right, but it was very difficult! We'll call it a D for now, and you'd better buck your ideas up if you plan to take an actual chemistry A-level any time soon.
You got about half right, not bad! But it was multiple choice, so a real exam is going to be harder.
You did better than just random guessing, so either you genuinely know a thing or two about chemistry, or you're really good at guessing. One of those qualities is going to lead you to a good mark in your real A-level chemistry, if you ever take it.
You got almost full marks, well done! Of course a real exam wouldn't be nine questions long and multiple choice, but you're on the right track for a good mark.
You got FULL MARKS! Congratulations! Of course a real exam wouldn't be nine questions long and multiple choice, but you're on the right track for a very good mark.
Kelly Oakes is science editor for BuzzFeed and is based in London.
Contact Kelly Oakes at email@example.com.
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