Atomic structure, isotopes, compounds, formulae and equations

Question 1

Atomic number

Answer 1

The number of protons in the nucleus of an atom.

Question 2

Bohr Model

Answer 2

Describes an atom as a small dense nucleus with electrons orbiting around the nucleus. This model explains different periodic properties of atoms.

Question 3

Electron

Answer 3

Negatively charged sub atomic particle.

Relative mass- 1/1836.

Question 4

Isotopes

Answer 4

Atoms of the same element with the same number of protons and electrons but different numbers of neutrons. Isotopes of an element have different masses.

Question 5

Mass number

Answer 5

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

Question 6

Mass spectrometry

Answer 6

An instrument which gives accurate information about relative isotopic mass and the relative abundance of isotopes.

Question 7

Neutron

Answer 7

Neutral subatomic particle.

Relative mass- 1.

Question 8

Proton

Answer 8

Positively charged subatomic particle.

Relative mass-1.

Question 9

Relative abundance

Answer 9

The amount of one substance compared with another.

Question 10

Relative atomic mass

Answer 10

The weighted mean mass of an atom compared with 1/12th mass of an atom of carbon 12.

Question 11

Relative isotopic mass

Answer 11

The mass of an atom of an isotope compared with 1/12th of an atom of carbon-12.

Question 12

Relative formula mass

Answer 12

The mass of the formula unit of a compound with a giant structure. For example NaCl has a relative formula mass of 58.44z

Question 13

Relative molecular mass (Mr)

Answer 13

The mass of a simple molecule.