Chemistry Defintions

Question 1

Atomic Number

Answer 1

This gives the number of protons in the nucleus of an atom.

Question 2

Mass Number

Answer 2

This gives the combined number of protons and neutrons in the nucleus of an atom.

Question 3

Relative Atomic Mass

Answer 3

The relative atomic mass of an element is the mass of 1 atom of the element compared to the mass of 1/12th of an atom of the Carbon-12 isotope

Question 4

Relative Molecular Mass

Answer 4

The relative molecular mass of a compound is the mass of one molecule of the compound compared to the mass of 1/12th of an atom of Carbon-12.

Question 5

Relative Formula Mass

Answer 5

The relative formula mass of the compound is the mass of one formula unit of the compound compared to the mass of 1/12th of an atom of Carbon-12.

Question 6

Isotopes

Answer 6

Isotopes are atoms of the same element with a different number of neutrons.

Question 7

Mole

Answer 7

One mole of any substance is that the mass of the material that contains as many elementary units as there are atoms in 12g of the carbon-12 isotope.

Question 8

Avogadro’s constant

Answer 8

The number of elementary particles present in one mole of a material.