AS OCR Chemistry Notes

Atomic Structure

ATOMIC NUMBER - The number of protons in the nucleus of the atom.

MASS NUMBER - The number of protons and neutrons in the nucleus of the atom.

ISOTOPES - Atoms of the same element with different numbers of neutrons

RELATIVE ISOTOPIC MASS - The mass of an isotope compared to 1/12th the mass of an atom of Carbon 12.

RELATIVE ATOMIC MASS - The weighted mean mass of an atom of an element compared to 1/12th the mass of Carbon 12

ORBITAL - A volume of space that can hold up to 2 electrons with opposite spins

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6

MOLES!

ACIDS + BASES

ACID - proton donor.

BASE - proton acceptor

ALKALI - a base that dissolves in water forming hydroxide ions (OH-(aq) ions)

ACIDS

HYDROCHLORIC ACID - HCl
SULPHURIC ACID - H2SO4
NITRIC ACID - HNO3

SALTS

H2SO4 ----> K2SO4
HCl ----> NaCl
HNO3 ----> Ca(NO3)2