1. Atoms, Molecules & Stoichiometry

Question 1

Relative atomic mass

Answer 1

The weighted average mass of naturally occurring atoms of an element on a scale where an atom of carbon-12 has a mass of exactly 12 units

Question 2

Relative isotopic mass

Answer 2

The mass of a particular isotope of an element on a scale where an atom of carbon-12 has a mass of exactly 12 units

Question 3

Relative molecular mass

Answer 3

The mass of one molecule of the compound on a scale where 1 mole of carbon-12 has a mass of exactly 12g

Question 4

Relative formula mass

Answer 4

The mass of one formula unit of an ionic compound on a scale where 1 mole of carbon-12 has a mass of exactly 12g

Question 5

Mole

Answer 5

The amount of substance that contains the same number of particles (atoms, molecules or ions) as the number of atoms in 12.0g of carbon-12

Avogadro constant = 6.02 × 10^23

Question 6

Empirical formula

Answer 6

The simplest whole number ratio of atoms of each element present in a compound

Question 7

Molecular formula

Answer 7

The formula showing the actual number of atoms of each element in one molecule of a compound