Section 5 - Solids, Liquids and Gases

Question 1

Formula for density

Answer 1

ρ(density) = m(mass) / V(volume)

Question 2

Units for density

Answer 2

g/cm³ OR kg/m³

Question 3

Formula for pressure

Answer 3

p(pressure) = F / A

Question 4

Unit for pressure

Answer 4

Pa

Question 5

What does 1 Pa =?

Answer 5

N/m²

Question 6

Formula for pressure difference

Answer 6

p = h * ρ * g

Question 7

Evaporation

Answer 7

Occurs at the surface of a liquid, and at lower temperatures than the liquid’s boiling point if:

• The particles are travelling in the right direction to escape the liquid
• The particles are travelling fast enough to overcome the forces of attraction of the other particles

Question 8

Particle theory

Answer 8

-Gases are made up of very small particles which are constantly moving in random directions - the particles take up little space; most of the gas is empty space

Question 9

The temperature of a gas(in kelvins) is…

Answer 9

proportional to the average kinetic energy of its particles

Question 10

Brownian motion

Answer 10

The constant random movement of particles in suspension due to collisions with other particles

Question 11

Absolute zero

Answer 11

0 K or -273°C

Question 12

Particle theory on collisions

Answer 12

• As gas particles move, they randomly collide
• Gas particles have mass, and therefore exert a force when they collide with another particle
• In a sealed container they collide with the containers walls, creating an outward force
• If you heat a gas, the particles have move kinetic energy

Question 13

Gas laws

Answer 13

1 - At constant temperature: p * V = constant

2 - At constant volume: p / T = constant