Definitions

Question 1

what’s an orbital?

Answer 1

A region of space which there is a (95, 98 or 99 percent) probability of finding two electrons.

Question 2

Ionisation energy

Answer 2

The energy needed to remove a mole of electrons from a mole of gaseous atoms to give a mole of gaseous 1+ ions

Question 3

Mass number

Answer 3

The weighted mean mass of an atom of an element on a scale which carbon 12 has a mass of 12 units.

Question 4

A mole

Answer 4

An amount of substance that contains the same number of particles as there are atoms in exactly 12g of C12 (6.02×10 23)

Question 5

Isotope

Answer 5

Isotopes of an element are atoms with the same number of protons but different numbers of neutrons.

Question 6

Relative isotopic mass

Answer 6

Mass of an atom of a particular isotope on a scale on which a carbon 12 has a mass of exactly 12 units.

Question 7

What’s an acid?

Answer 7

A proton (hydrogen ion) donor

Question 8

What’s a base?

Answer 8

A proton (hydrogen) acceptor.

Question 9

Molar Gas Volume

Answer 9

The volume per mole of gas molecules.

Question 10

A species

Answer 10

A type of partical that takes part in a reaction

Question 11

What is a salt?

Answer 11

an ionic compound where:

The positive ion, or cation is usually a metal or ammonium ion

the negative ion is derived from an acid

a H+ ion has been replaced by the positive ion

Question 12

water of crystallisation

Answer 12

Refers to water molecules that form an essential part if the crystalline structure of a compound