Definitions

Question 1

Physical Change

Answer 1

a change in which no new substance is formed

Question 2

Chemical change

Answer 2

a change in which one or more new substances are formed

Question 3

Physical properties of a substance

Answer 3

the properties that can be determined without the substance changing into another substance

Question 4

Chemical properites of a substance

Answer 4

the chemical reactions and the respective conditions in which each reaction takes place

Question 5

Element

Answer 5

An pure substance which cannot be broken down into any simpler substances by chemical methods

Question 6

Compound

Answer 6

a pure substance made of two or more elements chemical combined together

Question 7

Mixture

Answer 7

A mixture consists of two or more pure substances (elements or compounds) which have not been chemically combined together

Question 8

atom

Answer 8

the smallest part of an element which has the properties of that element

Question 9

atomic number

Answer 9

the number of protons in an atom

Question 10

Mass number

Answer 10

the total number of protons and neutrons in an atom

Question 11

Isotopes

Answer 11

different atoms of the same element with the same number of protons but different number of neutrons

Question 12

Relative isotopic mass (of a particular atom)

Answer 12

Relative isotopic mass of a particular atom is the mass of one atom of that isotope on the 12C scale

Question 13

Relative atomic mass

Answer 13

Relative atomic mass of an element is the weighed average of the isotope masses of its natural isotopes on the 12C scale

Question 14

Cations

Answer 14

Positive charge ions

Question 15

Anions

Answer 15

Negatively charged ions

Question 16

isoelectronic

Answer 16

Chemical species (ions or atoms) with the same electronic arrangement

Question 17

The maximum number of electrons found in the n th shell

Answer 17

2nn

Question 18

Extraction

Answer 18

The process of separating a metal from its ore

Question 19

Alloys

Answer 19

Mixtures of a metal with other elements

Question 20

Giant ionic structure

Answer 20

ionic solids made of ions packed closely together in a regular giant lattice

Question 21

Atomicity

Answer 21

the number of atoms in a molecule of an element or compound.

Question 22

Decantation

Answer 22

a quick but rough method of separating dense insoluble solids from a liquid or solution. The liquid on solution on top is carefully poured off

Question 23

A saturated solution

Answer 23

A solution in which the solvent has dissolved the maximum amount of solute it can at a particular temperature.

Question 24

Filtration

Answer 24

a method that separates an insoluble solid from a liquid or solution

Question 25

Evaporization

Answer 25

the change of a liquid to vapour at a temperature below its boiling point

Question 26

Crystallization

Answer 26

the process of forming crystals from a saturated solution

Question 27

Dative covalent bond

Answer 27

a covalent bond formed between two atoms where both electrons in the shared pair are contributed by the same atom