2.1.1 Atomic structure and Isotopes

Question 1

Define atomic number (Z)

Answer 1

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

Question 2

Define mass number (A)

Answer 2

The total number of protons and neutrons in the atom.

Question 3

Define isotopes

Answer 3

Isotopes are atoms of the same element that have the same number of protons, but a different number of neutrons.

Question 4

Why do isotopes have similar chemical properties?

Answer 4

Because they have the same electronic structure.

Question 5

Define relative isotopic mass

Answer 5

Relative isotopic mass is the mass of one isotope compared to 1/12 of the mass of one atom of carbon-12.

Question 6

Define relative atomic mass

Answer 6

Relative atomic mass is the weighted mean mass of one atom compared to 1/12 of the mass of one atom of carbon-12.

Question 7

Define relative molecular mass

Answer 7

Relative molecular mass is the average mass of a molecule compared to 1/12 of the mass of one atom of carbon-12.