help

This is for anyone doing the new OCR Chemistry spec starting this year.
Im revising but theres a hell of a lot our teacher has left out, and the first paper is around the corner. These parts of the spec especially have me baffled. Can anyone summarize what exactly you need to learn for:

"describe the relative energies of s,p,d orbitals for the shells 1,2,3, and the 4s and 4p orbitals"

"describe the redox reactions of metals with dilute hydrochloric acid and dilute sulfuric acids"

THANKS

OR IM GONNA GET OWNED IN THE EXAM
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Reply 1

skatealexia

Well for your first one, know the order which the subshells fill up.

1s2 2s2 2p6 3s2 3p6 3d5 4s2

The energy levels relatively go up, but the 4s subshell is in a lower energy level then the 3d subshell, so gets filled up with electrons first.

And:

Mg + 2HCl -> MgCl2 + H2

0 +1 -1 +2 -1 0

oxidation numbers, Mg is oxidised, Hydrogen is reduced...

Bubbles can be seen, due to the hydrogen gas.
Metal disappears, because it goes into a metal salt which is aqueous.
Mg + 2HN03 -> Mg( N03) 2 + H2

again, whats reduced what do you see happen ect.