C1.4 PRINCIPLES OF CHEMISTRY

Question 1

What is the difference between a mixture and a compound?

Answer 1

In a compound, the elements are CHEMICALLY COMBINED together.

In a mixture, the elements or components are NOT chemically combined together.

Question 2

Which sub-atomic particle has the smallest relative mass?

Answer 2

The electron has the smallest relative mass.

Question 3

Why do atoms have the same number of protons as electrons?

Answer 3

Atoms are neutral.

The number of positive charges ( protons ) must equal the number of negative charges ( electron ).

Question 4

. 27
An aluminium atom can be represented as Al.
14
What is aluminium ‘s nucleon number?

Answer 4

The nucleon number is 27

Question 5

. 27
An aluminium atom can be represented as Al.
14
How many neutrons does this atom of aluminium have?

Answer 5

14 neutrons

Question 6

How many electrons does magnesium have in its outer electron shell?

Answer 6

two electrons

Question 7

Stoichiometry is……….

Answer 7

a section of chemistry
that involves using relationships
between reactants and/or products
in a chemical reaction