Particle Model Of Matter

Question 1

Arrangement of particles in solid,liquid and gas

Answer 1

Solid- strong forces of attraction hodl the particle together in a fixed, regular arrangement. They vibrate

Liquids- Weaker forces of attraction, close together but they move past each other, irregular arrangements. Move in random direction and speeds

Gas- No forces of attrcation between particles, more enegy then solids and liquids and free ro move in random directions and speeds

Question 2

How is pressure created and how can it increase

Answer 2

Particles in gas collide against each other and sides of a container. Force is then exerted onto the surface so in a sealed container , outwards gas pressure is the total force exerted by all particles of gas on a unit area of the surface

Increasing temp kinetic energy increases of the particles increasing the pressure. Larger force exerte due to greater velocity.

Question 3

How to calculate density

Answer 3

Mass
Density=—————
Volume

Question 4

Required practical: measure density in different ways

1-4 find density of a solid

5-9 find density of a liquid

Answer 4

1) use a balance to measure mass of an object

2) If its an regular object measure its length,width and height with a ruler (calculate the volume)

3) If its an irregular object you can findits volume by filling up a eureka cup fully then placing the object inside gently. Place a measuring cup below the spout and the amount of water displaced is the volume of the object
Mass
4) use the calcuation to find density=—————–
Volume

5) Place measuring cylinder on a balance make sure it is at zero,

6) pour 10ml snd record the mass

7) Pour another 10 and repeat until full. Record the total volume and mass each time.
Mass
8) use the density formula Density =—————–
Volume

9) Take an average of tye calculated densities.

Question 5

What is the internal energy store and how can it be increased

Answer 5

Total energy that its particles have in their kinetic and potential energy stores

Heating a system will increase kinetic energy of the particles thus increasing the internal energy store which either raises the temp of the system or prodcues a change of state

Question 6

What is a change of state

Answer 6

Physical change of a substance in a different form (particle arrangement)- mass is conserved

Question 7

What is the flat part of a change of state graph represent and the increasing/decreasing lines

Answer 7

Flat part:Energy is transferred (changing state e.g melting or freezing)

Increasing/decreaisng part: particles forming or bonding in order to increase/ decrease internal energy to begin process of changing state

Question 8

What is specific latent heat and the name for SLH between a solid and liquid and between a liquid and gas

Answer 8

SLH of a substance is the amount of energy needed to change 1kg of it form one state to another without changing the temp

Specific latent heat of fusion - solid and liquid

specific latent heat of vaporisation- liquid and gas

Question 9

What is latent heat

Answer 9

The enrgy needed to change the state of a substance

Question 10

Calculation for specific latent heat

Answer 10

Energy = Mass X Specific latent heat

E=ML

Question 11

What is specific heat capacity and calculation

Answer 11

ΔE= M X cΔ X 0°

The amount of energy needed to raise the temperature of 1 kilogram of a substance by one degree celsius