Chemistry Test Y9 Term 1

Question 1

How is a compound made?

Answer 1

When atoms of different elements join together they make a compound.

Question 2

What are compounds?

Answer 2

Compounds are substances that contain atoms of at least two elements chemically combined.

Eg. Magnesium oxide consists of magnesium atoms and oxygen atoms chemically bonded together

Question 3

Atoms

Answer 3

There are over a hundred different types of atom, called elements, and each one has a symbol.
The atoms of a particular element are identical to each other.
Atoms are very, very small.

Question 4

When / how is a molecule formed?

Answer 4

A molecule is formed when atoms join together by chemical bonds.

Question 5

Compound or element?

Hydrogen

Answer 5

An element

Question 6

Compound or element?

Sodium chloride

Answer 6

A compound

Question 7

Compound or element?

Carbon

Answer 7

An element

Question 8

Compound or element?

Carbon dioxide- carbon and oxygen

Answer 8

A compound

Question 9

Beware! Many substances with only one name are actually compounds

Eg……

Answer 9

Water and methane

Question 10

When or how does a chemical reaction happen?

Answer 10

When the atoms in elements or compounds rearrange themselves to form new substances its called a chemical reaction.
The atoms are rearranged but no atoms are lost or made.

Question 11

Atom structure

Answer 11

Each atom is made of a nucleus- containing protons and neutrons- surrounded by electrons

Protons and electrons are oppositly charged.
Neutrons have no charge, meaning the nucleus of an atom is always positivly charged.
Atom has a neutral overall charge because it has the same number of electrons as protons.
Protons and neutrons have the same mass.
Electrons have such a small mass that this can usually be taken as zero.

Question 12

Atomic number

Answer 12

Is the number of protons in an atom. (Also known as the proton number) its the smallest number

Question 13

Mass number

Answer 13

The mass number of an atom is the total number of protons plus neutrons. (Also called the nucleon number) Its the bigger number

Question 14

Isotopes

Answer 14

Isotopes have the same atomic number, so they have the same number of protons and the number of protons and electrons are the same, but a different mass number, meaning different number of neutrons

Question 15

Common ions

Names:

• copper(II)
• Iron(II)
• Iron(III)
• carbonate
• Hydroxide
• Nitrate
• Ammonium
• Sulfate
• Hydrogencarbonate

Answer 15

Cu2+
Fe2+
Fe3+
Co32-
OH-
NO3-
NH4+
SO42-
HCO3-

Question 16

An important feature of subatomic particles is their electrical charge:

Answer 16

Particle proton neutron electron

Charge +1 0 -1

Question 17

When or how does atoms turn into ions

Answer 17

Atoms turn into ions when they lose or gain electrons.

Question 18

When is a covalent bond formed

Answer 18

A covalent bond is formed between non-metal atoms, which combine together by sharing electrons.
Covalent bonds have no free electrons and no ions so they do not conduct electricity.

Question 19

Ionic compounds

Answer 19

Do not conduct electricity when solid because the ions are packed together and can not move.

When molten, lattice breaks up and ions are free to move, because they are charged particles they can carry an electric current.

Usually soluble in water because water molecules have a slight electrical charge and can attract the ions away from the lattice

When dissolved, the ions are free to move and can carry an electric current

Brittle, they shatter when hit, when the lattice is hit, a layer of ions shift so that ions with the same charges are lined up together. These like charges repel each other and thereby splitting the lattice.

Question 20

Metal ions

Answer 20

Metal atoms may lose electrons. The atom then has more protons than electrons and so it will be positively charged, a positive ion

Question 21

Non-metal ions

Answer 21

Non-metal atoms may gain electrons and become negatively charged

Question 22

Covalent bonding

Answer 22

Non metals

Question 23

Metallic bonding

Answer 23

Metals

Question 24

Ionic bonding

Answer 24

Non-metals and metals

Is when atoms turn into ions when they lose or gain electrons

Question 25

Compounds that contain ions are called……

Answer 25

Ionic compounds

Question 26

Balance equation for reaction between halogens and metal halides

Answer 26

CL2+2NaBr——->2NaCl+Br2

Question 27

Metallic bonding

Answer 27

The particles in a metal are held together by strong metallic bonds.
The outer electrons seperate from their atoms and become delocalized, creating a sea of electrons. The atoms become positive ions and are attracted to the electrons, this is metallic bonding