Module 2: Quantitative Chemistry definitions

Question 1

What is the Relative Atomic Mass (Ar)?

Answer 1

The mean weighted mass of one atom of an element on a scale where the mass of one atom of Carbon-12 is exactly 12.

Question 2

What is the Relative Isotopic Mass (Ir)?

Answer 2

The mass of one atom of a specific isotope of an element on a scale where the mass of one atom of Carbon-12 is exactly 12.

Question 3

What is the Relative Molecular Mass (Mr)?

Answer 3

The mean weighted mass of one molecule of a compound on a scale chosen so that the mass of one atom of Carbon-12 is exactly 12.

Question 4

What is a Mole?

Answer 4

The amount of substance that contains as many particles as there are atoms in 12g of Carbon-12.

Question 5

What is the Molar Mass (M)?

Answer 5

The amount of substance with a mass in grams equal to the Formula Mass (MR).

Question 6

Define Avogrado’s Constant?

Answer 6

Exactly 12g of carbon-12 contains 6.02x10^23 atoms.

Question 7

What is a Isotope?

Answer 7

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.