2. Seawater - 2.1. The water cycle

Question 1

What are atoms?

Answer 1

The tiny particles that make up all material

Question 2

What are molecules?

Answer 2

Particles formed from atoms

Question 3

What is particle theory?

Answer 3

The idea that we can describe all materials as a collection of very many tiny particles that are constantly moving

Question 4

What happens when a material is heated?

Answer 4

The particles gain more kinetic energy and move faster and the temperature of the material increases

Question 5

What unit measures the kinetic energy of the particles in a material?

Answer 5

Degrees Celsius

Question 6

What are the 3 different physical states?

Answer 6

Solid, liquid and gas

Question 7

Describe the arrangement of particles in a solid

Answer 7

Particles closely packed together; not enough space to move past each other

Question 8

Describe the arrangement of particles in a liquid

Answer 8

Particles closely packed together; just enough space to move past each other

Question 9

Describe the arrangement of particles in a gas

Answer 9

Particles far apart from each other; lots of space for particles to move past each other

Question 10

Describe the motions of particles in a solid

Answer 10

Particles vibrating against each other in fixed positions

Question 11

Describe the motions of particles in a liquid

Answer 11

Particles vibrating against each other and flowing past each other

Question 12

Describe the motions of particles in a gas

Answer 12

Particles moving fast, colliding with each other

Question 13

In which 2 physical shapes does a material take the shape of its container?

Answer 13

Liquid and gas

Question 14

In which 2 physical shapes does a material have a fixed volume?

Answer 14

Solid and liquid

Question 15

What happens when a solid is heated?

Answer 15

The vibrations increase and the solid expands slightly. With enough energy, the vibrations create enough space between the particles so they can move past each other - it’s now a liquid.

Question 16

What is the melting point?

Answer 16

The temperature at which a solid becomes a liquid

Question 17

What is latent heat energy?

Answer 17

The energy transferred to separate particles enough to move past each other

Question 18

What happens to the temperature of a material as it is melting and at its boiling point?

Answer 18

It stops increasing (until the material has melted/evaporated)

Question 19

What is evaporation?

Answer 19

When some liquid particles at the surface have more energy than others and escape from the liquid

Question 20

What accelerates the rate of evaporation?

Answer 20

Warmth

Question 21

Explain why a liquid doesn’t need to boil to turn to gas

Answer 21

Evaporation happens when particles of liquid at the surface have enough kinetic energy to escape

Question 22

What is the boiling point?

Answer 22

When all particles in a liquid have enough energy to evaporate (and the liquid turns to gas)

Question 23

What is the significance of zero degrees Celsius and 100 degrees Celsius?

Answer 23

They are the melting and boiling points of pure water

Question 24

What is the role of evaporation in the water cycle?

Answer 24

It transfers water into the atmosphere

Question 25

What is condensation?

Answer 25

Loss of latent heat in a gas until it turns into a liquid

Question 26

What happens when a liquid cools down and reaches the melting point?

Answer 26

The liquid becomes a solid

Question 27

What happens where a soluble solid is placed into a liquid?

Answer 27

The liquid particles allow the solid particles to mix with them (dissolve)

Question 28

What is diffusion?

Answer 28

When a soluble solid first is placed in a liquid, the solid particles are in high concentration where liquid meets the solid. Diffusion in the solid particles slowly moving away from each other

Question 29

What can dissolve into liquids?

Answer 29

Soluble solids and gases

Question 30

How to dissolved particles move in a liquid?

Answer 30

From a high concentration area (where they first come into contact with the liquid) to a low concentration area

Question 31

How is water moved around in the oceans?

Answer 31

In currents

Question 32

What factors affect how fast water evaporates?

Answer 32

Temperature (higher temperature = faster evaporation) Wind speed (faster winds = more energy = faster evaporation) Humidity (more humidity = more vapour in the air = slower evaporation)