Unit 1

Question 1

Acidic

Answer 1

Solutions that have a higher concentration of H+ (aq) ions than OH- (aq) ions and have a pH below 7

Question 2

Alkaline

Answer 2

Solutions that have a higher concentration of OH- (aq) ions than H+ (aq) ions and have a pH above 7

Question 3

Catalyst

Answer 3

Substances that speed up chemical
reactions but can be recovered
chemically unchanged at the end of the
reaction.

Question 4

Covalent bond

Answer 4

Forms when two positive nuclei are held together by their common attraction for a shared pair of electrons.

Question 5

Diatomic Molecules

Answer 5

7 elements exist as diatomic molecules
through the formation of covalent
bonds: H2, N2, O2, F2, Cl2, Br2, I2

Question 6

Ion

Answer 6

Formed when atoms lose or gain electrons to obtain the stable electron arrangement of a noble gas

Question 7

Ionic bond

Answer 7

The electrostatic attraction between
positive and negative ions

Question 8

Isotope

Answer 8

Atoms with the same atomic number but different mass numbers, or Atoms with the same number of protons but different numbers of neutrons

Question 9

Mole

Answer 9

The mass of any substance, in grams equal to the gram formula mas

Question 10

Neutral

Answer 10

A solution that has equal concentrations of H+(aq) and OHˉ(aq) ion

Question 11

Neutralisation reactions

Answer 11

A reaction in which a base reacts with an acid to form water. A salt is also formed in this reaction

Question 12

Spectator ion

Answer 12

Spectator ions are ions that remain unchanged by the reaction