Science Exam Revision

Question 1

Reactant

Answer 1

A substance that takes part in a chemical reaction

Question 2

Catalyst

Answer 2

A substance used to increase the speed of a chemical reaction. It is not used itself

Question 3

Decomposition

Answer 3

When one substance breaks down into 2 or more

Question 4

Product

Answer 4

The substance produced from a chemical reaction

Question 5

Displacement reaction

Answer 5

One element replaces another element in a chemical reaction

Question 6

Synthesis

Answer 6

Hydrogen + oxygen make water

Question 7

Precipitation

Answer 7

A solid formed from 2 liquids

Question 8

Combustion

Answer 8

Combination of a substance with oxygen+heat+light

Question 9

Anion

Answer 9

Negatively charged ion

Question 10

Cation

Answer 10

A positively charged ion

Question 11

Electron

Answer 11

A negatively charged particle

Question 12

Nucleus

Answer 12

The centre of an atom containing protons+neutrons

Question 13

Atomic mass

Answer 13

Number of protons and neutrons in an atom

Question 14

Valence

Answer 14

Electrons in the outer shell

Question 15

Ion

Answer 15

An atom with a positive or negative charge

Question 16

Ground state

Answer 16

A metal atom before it is heated

Question 17

Metalloids

Answer 17

Element with metal and non metals

Question 18

Malleable

Answer 18

A material that can be easily bent

Question 19

Which ways do groups go in the periodic table?

Answer 19

Down

Question 20

Which ways do periods go in the periodic table?

Answer 20

Across

Question 21

Atomic number

Answer 21

Number of protons. Equal to number of electrons

Question 22

With an anion, do you add or take away electrons

Answer 22

Add

Question 23

Ionic bonds

Answer 23

When 2 or more elements gain or remove electrons so they both have full outer shells (non metal+metal)

Question 24

Covalent bonds

Answer 24

When 2 or more compounds share electrons so they both have full outer shells. (Non metals)