Key Words

Question 1

Particle model

Answer 1

A way of showing how particles in a state of matter are arranged and move

Question 2

States of matter

Answer 2

Solid, liquid and gas – 3 “states” which a substance can occur as, depending on it’s melting and
boiling point

Question 3

Chemical reaction

Answer 3

Bonds between atoms are broken and remade, making new substances

Question 4

Physical change

Answer 4

No chemical bonds are broken – the substances may change state but will not change it’s chemical
composition

Question 5

Atoms

Answer 5

Smallest occurring particle of an element. Approximately 1 x 10-10 m

Question 6

Electrostatic forces

Answer 6

Forces between particles. Strong in solids, weak in gases

Question 7

Model limitations

Answer 7

Areas where a model does not give a true or accurate representation of something.

Question 8

atom

Answer 8

smallest particle of an element -with a nucleus of protons and neutrons, surrounded by electrons

Question 9

Atomic number

Answer 9

number of protons in the nucleus of an atom

Question 10

electron

Answer 10

subatomic particle surrounding the atom’s nucleus, has a relative charge of -1, and very small mass

Question 11

element

Answer 11

substance whose atoms have the same atomic number

Question 12

ion

Answer 12

charged particle formed when an atom, or group of atoms, loses or gains electrons

Question 13

isotope

Answer 13

Same element with the same protons and electrons, but different numbers of neutrons

Question 14

Mass number

Answer 14

number of protons and neutrons in a nucleus

Question 15

molecule

Answer 15

particle consisting of two or more non-metal atoms chemically joined together by covalent bonds

Question 16

Plum-pudding model

Answer 16

outdated model of the atom in which electrons are embedded in a sphere of positive charge

Question 17

shell

Answer 17

region of space in an atom that can hold a certain number of electrons