Clarification of Terms

Question 1

Define a Molecular ion

Answer 1

Two or more atoms covalently bonded with an overall charge.

Question 2

Define Avogadro’s Constant (6.02x10^23)

Answer 2

Number of atoms in 12.000g in a single Carbon-12 atom.

Question 3

Define a Mole

Answer 3

The amount of substance which contains the Avogadro’s constant of atoms, molecules or groups of ions.

Question 4

Define Molar mass

Answer 4

The mass of one mole of a substance.

Question 5

Define Anhydrous (salt)

Answer 5

A salt which contains no water of crystallisation.

Question 6

Define Hydrated (salt)

Answer 6

A salt which contains water of crystallisation.

Question 7

Define the Atomic Number

Answer 7

The number of protons in (the nucleus of) an atom.

Question 8

Define the Mass Number

Answer 8

The total number of protons and neutrons in (the nucleus of) an atom.

Question 9

Define Relative Atomic Mass (RAM)

Answer 9

The average (weighted mean) mass of an atom of an element relative to one-twelfth of the mass of an atom of Carbon-12

Question 10

Define Relative Isotopic Mass (RIM)

Answer 10

The mass of the atom of an isotope of an element relative to one-twelfth of the mass of an atom of Carbon-12.

Question 11

Define an Isotope

Answer 11

An atom with the same atomic number but a different mass number (same protons, different neutrons).

Question 12

Relative formula
mass (RFM)

Answer 12

The average (weighted mean) mass of a formula unit relative to one-twelfth of the mass of an atom of Carbon-12

Question 13

Relative molecular
mass (RMM)

Answer 13

The average (weighted mean) mass of a molecule relative to one-twelfth of the mass of an atom of Carbon-12.

Question 14

Define Water of Crystallisation

Answer 14

The water which is chemically bonded within a crystal structure.