1.1 Definitions

Question 0

Define the atomic (proton) number

Answer 0

The atomic number is the number of protons in the nucleus of an atom.

Question 1

Define an isotope

Answer 1

Isotopes are atoms of the same element with different numbers of neutrons.

Question 2

Define the mass number

Answer 2

Mass number is the number of particles in the nucleus.

Question 3

Define an ion

Answer 3

An ion is a positively or negatively charged atom or (covalently bonded) group of atoms (a molecular ion).

Question 4

Define the relative isotopic mass

Answer 4

The relative isotopic mass is the mass of an isotope compared with 1/12 of the mass of an atom of carbon-12.

Question 5

Define relative atomic mass

Answer 5

The relative atomic mass is the weighted mean mass of an atom of an element compared with 1/12 of the mass of carbon-12.

Question 6

Define relative molecular mass

Answer 6

The relative molecular mass is the weight mean mass of a molecule compared with 1/12 of the mass of an atom of carbon-12.

Question 7

Define the relative formula mass

Answer 7

The relative formula mass is the weighted mean mass of a formula unit compared with 1/12 of the mass of an atom of carbon-12.