S1.1 - introduction to the particulate model of matter

Question 1

What is an element?

Answer 1

Primary constituents of matter which cannot be broken down into simpler substances.

Question 2

What is a mixture?

Answer 2

One or more elements or compounds in no fixed ratio that aren’t chemically combined, so can be separated from physical methods.

Question 3

What is a compound?

Answer 3

Two or more atoms of different elements chemically bonded together in a fixed ratio.

Question 4

What is the difference between a homogeneous and heterogeneous mixture?

Answer 4

Heterogeneous - non-uniform composition and substances have different interactions such as oil and water.
Homogeneous - uniform composition where all substances have the same properties and interactions such as alloys.

Question 5

What is crystallization?

Answer 5

Crystallization - using evaporation and condensation to collect a pure solid.

Question 6

What is filtration?

Answer 6

Filtration - separating an insoluble solid from a liquid using a filter paper and funnel.

Question 7

What is distillation?

Answer 7

Distillation - separates mixture of solvents with different boiling points.

Question 8

What is chromatography?

Answer 8

Chromatography - separates substances with different solubilities.

Question 9

What is the kinetic molecular theory?

Answer 9

Kinetic molecular theory - a model used to explain the physical properties of matter and their changes of state.

Question 10

What are the properties of solids?

Answer 10

• particles arranged closely in a regular pattern with all particles touching
• particles vibrate in a fixed position
• fixed shape and volume

Question 11

What are the properties of liquids?

Answer 11

• particles closely arranged but not in a regular pattern
• no fixed shape and volume
• move slightly

Question 12

What are the properties of gases?

Answer 12

• particles fully spread out
• particles move around quickly
• no fixed shape and volume
• can be compressed

Question 13

What is kinetic energy?

Answer 13

Kinetic energy - energy from the movement of particles with an inverse relationship to mass and velocity.

Question 14

What is the boiling point?

Answer 14

Boiling point - temperature at which vapor pressure is equal to external pressure.

Question 15

What is melting and freezing?

Answer 15

Melting - solid to liquid
Freezing - liquid to solid

Question 16

What is evaporation and condensing?

Answer 16

Evaporation - liquid to gas
Condensation - gas to liquid

Question 17

What is sublimation and deposition?

Answer 17

Sublimation - solid to gas
Deposition - gas to solid

Question 18

What is the difference between evaporation and boiling?

Answer 18

Evaporation - occurs at the top layer of the liquid at a range of temperatures.
Boiling - occurs throughout the liquid at a certain temperature.

Question 19

What is vapor pressure?

Answer 19

Vapor pressure - pressure exerted by the gas in equilibrium with a solid or liquid in a closed container at a given temperature.

Question 20

What is the relationship between temperature and vapor pressure?

Answer 20

A small increase in temperature can cause a significant increase in vapor pressure.

Question 21

What happens to pressure and boiling points at higher altitudes?

Answer 21

Lower altitude = higher pressure = higher boiling points
Higher altitude = lower pressure = lower boiling points

Question 22

What is temperature?

Answer 22

Temperature - measure of the average kinetic energy.

Question 23

What is absolute temperature?

Answer 23

Absolute temperature - lowest temperature when there is no movement of particles at -273K

Question 24

How can you convert between K and C?

Answer 24

K –> C = -273.15
C –> K = +273.15

Question 25

How can you describe the changing states from a graph?

Answer 25

1) As energy increases, temperature increases in the solid state. 2) Melting - solid to liquid with no change in temperature. 3) As energy increases, temperature increases in the liquid state. 4) Boiling - liquid to gas with no change in temperature. 5) As energy increases, temperature increases in the gaseous state.