Chemistry Year 9

Question 1

What is an isotope

Answer 1

Isotopes are atoms with the same number of protons, but a different number of neutrons. They have
the same atomic number, but a differing mass number.

Question 2

How to find neutrons

Answer 2

Mass number- atomic number

E.g
35-17=18 (isotope)

Question 3

Nucleus

Answer 3

is found in the centre of the atom, and contains protons (+) and neutrons (neutral).

Question 4

Law of conversation of mass

Answer 4

Mass of reactants will always equal the mass of the product

Question 5

Exothermic Reaction

Answer 5

Release energy when the reaction occurs
Increase in temperature
E.g Respiration

Question 6

Endothermic Reaction

Answer 6

Refer to chemical reactions that absorb energy in order for the reaction to occur
Decrease in temperature
E.g photosynthesis

Question 7

Chemical reactions signs

Answer 7

Colour change
Heat released/ absorbed
Formation of gas

Question 8

Properties of an acid

Answer 8

Sour taste 
React with metals =hydrogen gas
React with calcium carbonate = carbon dioxide 
Turn blue litmus paper red
React with bases ( neutralisation)

Question 9

Properties of a base

Answer 9

Bitter taste
Turn red litmus paper blue
React with acids in a process (neutralisation)

Question 10

What happens when a metal reacts with an acid?

Answer 10

produce a salt and hydrogen gas

Question 11

What happens when an acid reacts with calcium carbonate?

Answer 11

Produce calcium salt, water and carbon dioxide

Question 12

Neutralisation meaning

Answer 12

a chemical reaction in which an acid and a base react quantitatively with each other

Question 13

What’s an Element

Answer 13

Only 1 type of atom

Molecule

E.g = zinc
🔴🔴

Question 14

What a Compound

Answer 14

More than 2 elements chemically combined

A molecule

Can’t be separated physically
E.g = water
⚫️🔵

Question 15

What are mixtures

Answer 15

2 or more different substances that are not chemically combined easily separated physically

Not a molecule

E.g = salt water
⚫️. 🔵
. 🔺. 🔶⚪️

Question 16

Protons

Answer 16

Positive charge

Question 17

Neutrons

Answer 17

Neutral charge

Question 18

Electrons

Answer 18

Negative charge

Question 19

Electrons are found?

Answer 19

Around the nucleus

Question 20

What particles do you find in the nucleus of an atom?

Answer 20

Neutrons an protons

Question 21

What are shells?

Answer 21

Energy levels

Hold a maximum of … electrons

Question 22

Mass number

Answer 22

Protons + Nuetrons

Question 23

What is a valence electron

Answer 23

Electrons involved in chemicals reactions

Last shell

Question 24

Alkali metals

Answer 24

Group 1

E.g sodium

Question 25

Alkaline metals

Answer 25

Group 2 E.g Calcium

Question 26

Halogens

Answer 26

Group 17 | E.g fluorine

Question 27

Nobel gases

Answer 27

Group 18 | E.g Helium

Question 28

What is meant by a ‘group’ in the Periodic Table?

Answer 28

elements in each group have the same number of electrons in the outer shell Last shell (1) = groups (1) E.g Groups Periods Name 2,8,1 1 3 Sodium

Question 29

What is meant by a ‘row’ in the Periodic Table?

Answer 29

number of occupied shell 3 shells= 3periods E.g Groups Periods Name 2,8,1 1 3 Sodium

Question 30

Cation?

Answer 30

Metal

Question 31

Anion?

Answer 31

Non metal

Question 32

Name a salt

Answer 32

Iron chloride = IDE ENDING

Question 33

Iron + chlorine + oxygen =

Answer 33

Iron chlorate

Question 34

Example of a base | 2

Answer 34

Soap, drain cleaner

Question 35

Example of acids | 2

Answer 35

Lemon, batteries

Question 36

When an acid reacts with a base, what is formed?

Answer 36

When acids and bases mix they cancel out the effects of each other. This reaction is is called neutralisation reaction Acid + Base = salt water

Question 37

What are the 3 different | types of radiation and what materials can stop the radiation?

Answer 37

alpha particles- stopped by clothing and paper etc. beta particles- stopped by a few millimetres gamma rays- stopped by several centimetres of lead or meters of concrete

Question 38

What are the 3 different types of radiation and what materials can stop the radiation? 25.

Answer 38

O

Question 39

What does the half-life of a radioactive element mean?

Answer 39

The time taken for half of all the nuclei in a sample of a radioisotope to disintegrate or decay is known as its half-life. Half-lives can vary from microseconds to billions of years.

Question 40

Control variable

Answer 40

Stays the same

Question 41

Some of death

Answer 41

Area around microbes that have been killed

Question 42

Pathogen

Answer 42

Microorganisms that cause disease

Question 43

Epidemic

Answer 43

An outbreak of a disease or illness that spreads rapidly among individuals in an area or population at the same time. In a community

Question 44

Virulence

Answer 44

the severity or harmfulness of the disease

Question 45

Host

Answer 45

An animal or plant that carries or contains a parasite

Question 46

acid + base

Answer 46

salt + water

Question 47

acid + metal

Answer 47

salt + | hydrogen

Question 48

acid + salt + metal carbonate

Answer 48

+ water + salt + | carbon dioxide

Question 49

Activation energy

Answer 49

The amount of energy required for a reaction to begin

Question 50

Independent Variable

Answer 50

One thing you choose