Chemistry

Question 1

Periods

Answer 1

A period is a horizontal row of the Periodic table. A new period begins when a new electron energy level begins filling with electrons.

Question 2

Groups

Answer 2

A group is a vertical column of the Periodic table. Groups all share the same number of valence electrons and have similar chemical properties.

Question 3

Atomic number

Answer 3

The number of protons in the nucleus of an atom, which is characteristic of a chemical element and determines its place in the periodic table.

Question 4

Relative atomic mass

Answer 4

Is a measure of how heavy atoms are, which is determined by the number of protons and neutrons in an atom.

Question 5

Alkali metals

Answer 5

The metals which are found in group 1 of the periodic table. These are characterised by a very high reactivity, even in water, due to their single valence electron.

Question 6

Alkaline earth metals

Answer 6

The metals which are found in group 2 of the periodic table. These are characterised by a high reactivity in acid and weak reactivity with water.

Question 7

Halogen

Answer 7

Non-metal elements in group 17 of the periodic table. These are brightly coloured elements.

Question 8

Nobel gasses

Answer 8

Non-metal elements in group 18 of the periodic table. These do not react easily and are considered inert because of their full valence shell of electrons.

Question 9

Transition metal block

Answer 9

The block of elements in the middle of the periodic table. These substances tend to form colourful solutions when dissolved in water.

Question 10

Lustre

Answer 10

Shine or sheen produced from reflected light.

Question 11

Malleable

Answer 11

A property of metals where they are able to be hammered and pressed into shape without breaking or cracking.

Question 12

Ductile

Answer 12

A property of metals where they are able to be drawn into thin wires without splitting or snapping.

Question 13

Molecules

Answer 13

A group of atoms that are chemically bonded which form discrete, fundamental particles that can take part in chemical reactions.

Question 14

Ionic compounds

Answer 14

Compounds formed between a negative ion (anion) and a positive ion (cation) whose electrostatic attraction is the basis of their ionic bond.

Question 15

Neutralisation

Answer 15

A reaction between an acid and a base which results in salt and water and a more neutral pH.

Question 16

Salt

Answer 16

Result of a neutralisation reaction where the cation from an acid is ionically bonded to the anion of a base.

Question 17

Enzymes

Answer 17

Biological catalysts which allow biological reactions to occur much faster and with a smaller activation energy.

Question 18

Brittle

Answer 18

A hard substance which resists change in shape, but small distortions in its structure cause widespread cracking.

Question 19

Conductors

Answer 19

Allow energy to easily flow through the substance with little resistance. Energy may be in the form of electricity or heat.