Chemistry (Y9)

Question 1

What are the 3 states of matter?

Answer 1

Solid,liquid and gas

Question 2

Components of a solid?

Answer 2

Fixed,unless you apply force.vibrates vigerously.doesnt flow.cannot be compressed.has a fixed shape and volume.

Question 3

Components of a liquid?

Answer 3

No fixed shape but a fixed volume. Cannot be compressed. does flow. Takes the shape of the bottom of its container.

Question 4

Components of a gas?

Answer 4

No fixed shape or volume. Can be compressed and does flow. Takes shapw of whole container.

Question 5

Are boiling and condensation point the same?

Answer 5

Yes=100 degrees celcius

Question 6

Are melting and freezing point the same?

Answer 6

Yes=0 degrees celcius

Question 7

1)Solid to liquid is called?
2)Liquid to gas is called?
3)Gas to liquid is called?
4)Liquid to solid is called?
5)Solid to gas is called?
6)Gas to solid is called?

Answer 7

1)melting
2)boiling
3)condensing
4)freezing
5)sublimation
6)deposition

Question 8

Define element?

Answer 8

A chemical substance made up of only 1 type of atom. It is a pure substance found in the periodic table.

Question 9

Define compound?

Answer 9

2 or more elements that have been chemically bonded/joined together.

Question 10

Defone mixture?

Answer 10

2 or more elements that have been mixed together but not chemically bonded/joined together.

Question 11

What direction is a group and a period?

Answer 11

Groups (collum) vertically down (look like a l)
Periods (rows) horizontally across (look like a -)

Question 12

Examples of elements?

Answer 12

Chlorine (Cl)
Oxygen (O2)
Nitrogen (N)

Question 13

Examples of compounds?

Answer 13

Carbon dioxide (CO2)
Pure water (H2O)

Question 14

Examples of mixtures.

Answer 14

Soil
Air
Sea water

Question 15

What is the atomic number?

Answer 15

The number of protons in an atom is known as the atomic number of the proton number (example=atomic number of carbon is 6)

Question 16

What is the mass number?

Answer 16

It is the larger of the 2 numbers shown in most periodic table. It is the sum of the protons and neutrons (e.g carbons Mass Number is 12)

Question 17

1) Protons + neutrons =
2) Lithium= 3 protons + 4 neutrons =
3) Hydrogen= 1 proton + 0 neutrons =
4) Aluminium= 13 protons + 14 neutrons =

Answer 17

1) Mass number (protons +neutrons)
2) 7
3) 1
4) 27

Question 18

What is the relative mass and charge of protons,neutrons and electrons?

Answer 18

Relative mass:

Protons=1
Neutrons=1
Electrons=almost 0

Charge:

Protons=+1
Neutrons=0
Electrons=-1

Question 19

What is a balanced equation? (With example)

Answer 19

A balanced equation is a equation with the same number of each type of atom on either side of the equation. A balanced equation must be in its simplist whole number ration.

O2H + O = H + O2 unbalanced
O2H + 2O = H + 2O2 balanced

Question 20

How do you work out the relative formula mass of something?

Answer 20

To work out the relative formula mass/ molar mass, we add together the atomic mass (or mass number) for all the elements in the formula:

Formula mass/molar mass of H2O=18

(2 x H) + (1 x O)
(2 x 1) + (1 x 16)
2 + 16 =18

Question 21

What does AUM stand for?

Answer 21

Atomic Mass Unit

Question 22

Work out molar/relative formula mass of these…

1)C2H5OH
2)C2H6

Answer 22

1)46=(2x12)+(6x1)+(1x16) Carbon (C)=12,hydrogen (H)=1,Oxygen (O)=16
2)30=(2x12)+(6x1)

Question 23

What is a mole?

Answer 23

The amount of substance in the relative atomic or formula mass of a substance in grams. E.g

Carbon
12g=1 mole of carbon

Question 24

Calculate the number of moles in 9.00g of H2O?

Answer 24

(Ox1)+(Hx2)=
(1x16)+(2x1)=
(16+2)=18
18x9g=162 moles in 9grams of H2O

Question 25

What is the method for calculating the number of moles of a material?

Answer 25

1)find atomic/formula mass of each element 2)add up atomic mass 3)times the sum of the atomic mass by the number of mass (e.g 8.00g,100.0g) and you will get your answer.

Question 26

How do you know what 1 mole of any atom is?

Answer 26

The atomic mass of any element in grams (g) is 1 mole of atoms of that element. E.g 12g of carbon = 1 mole of carbon atoms 32g of Oxygen = 1 mole of Oxygen atoms

Question 27

How do you find the number of moles?

Answer 27

Number of moles = Mass(g) / relative atomic mass

Question 28

How do you find the mass (g)?

Answer 28

Mass (g) = number of moles x relative atomic mass

Question 29

State the melting and boiling points of pure substances are fixed?

Answer 29

Pure substances consist of only one kind of matter. All the particles of a pure substance are alike. It has a definite composition and similar properties. These are the reasons why pure substances have fixed melting and boiling point.

Question 30

How do you find the number of particles?

Answer 30

Number of moles x 6.02x10~23

Question 31

How do you find the percentage of an element in a compound?

Answer 31

Mass of element in compound / Relative formula mass of compound E.g Find the percemtage of oxygen in sulfur dioxide SO2 S=(1x32) O2=(2x16) 32+32=64 32/64=1/2=50% / = divide

Question 32

What is melting?

Answer 32

It is when particles in a solid gain heat energy and vibrate more vigourously. When this happenes, a solid changes state and becomes liquid.

Question 33

What is freezing?

Answer 33

It is when particles in a liquid lose heat energy and move less quickly. When this happens,a liquid changes state and becomes solid.

Question 34

What is evaporation?

Answer 34

It is when particles in a liquid gain heat energy and more move quickly. When this happenes, a liquid changes state and becomes a gas.

Question 35

What is condensation?

Answer 35

It is when particles in a gas lose heat energy and move more slowly. When this happenes, a gas changes state and becomes a lquid.

Question 36

What is sublimation?

Answer 36

It is when a solid changes state and becomes a gas without becoming a lquid. In normal conditions, it is rare!

Question 37

What is the nuclues of an atom?

Answer 37

It is the dense 'core' at the centre of an atom which contains protons and neutrons.

Question 38

What are electrons?

Answer 38

Electrons are tiny particles that are spread out in 'shells' around the outside of the atom. Electrons are negatively charged and have hardly any mass.

Question 39

What are protons?

Answer 39

Protons are positively charged particles in the nuclues of the atom. They have a mass of 1.

Question 40

What are neutrons?

Answer 40

Neutrons are neutral particles in the nuclues of the atom. They have a mass of 1.

Question 41

What do we call the substances that react together during a chemical reaction?

Answer 41

The reactants

Question 42

How do you find percentage by mass equation?

Answer 42

% by mass= (atomic mass (total) / formula mass) x 100

Question 43

What do we call the substances produced during a chemical reaction?

Answer 43

The products