Thermal energy

Question 1

Kinetic energy eqaution

Answer 1

E = 1 mv sqaured
2

Question 2

What does theoretical mean

Answer 2

Based on ideas

Question 3

What does empirical mean

Answer 3

Based on proof

Question 4

What did we see when we looked through the microscope at the smoke particles

Answer 4

When we looked through the microscope we saw tiny white smoke particles moving in random directions because they were bouncing off of the air particles the reason they move in this motion is because they have more impact on one side of the atom and the other causing a resultant force where the more impacted the smoke moves in that direction which changes randomly so there is a zigzag motion

Question 5

What is the boiling point and melting point of argon oxygen and water

Answer 5

Boiling. Melting
Argon. -185. -189
Oxygen -183. -218
Water. 100. 0

Question 6

Definition of temperature

Answer 6

It is the degree of hotness of an object and it can be measured by thermometer temperature can be expressed by Celsius Fahrenheit or kelvin scale

Question 7

Definition of heat

Answer 7

It is the energy which travels from high temperature to low temperature in a matter it is also called thermal or internal energy it is measured in joules

Question 8

What is Brownian motion

Answer 8

Random movement of particles of liquids or gases

Question 9

What is the proof of kinetic theory

Answer 9

Is Brownian motion less smoke particles move in random direction is hitting other particles as well as that when you heat atoms up the pressure builds causing the atoms to move quicker therefore more kinetic energy

Question 10

Proof of kinetic theory examples

Answer 10

Brownian motion
Particles moving around create pressure less particles high up less pressure expansion of gases in aeroplane
Pumping up a timer
Expansion of a liquid
Expansion of a solid

Question 11

What is absolute zero

Answer 11

0k or -273 degrees Celsius

Question 12

How does the expansion of metal happen when heated

Answer 12

It’s a metal is heated the particles inside it gain more kinetic energy which means they move quicker therefore the increase in speed hitting each other more times and therefore expanding the solid

Question 13

The expansion of liquids

Answer 13

When the liquid is heated the molecules have more energy and move more vigourously the movement of the molecules overcome the forces of attraction between the molecules allowing them to move freely loss the volume of the liquid increases

Question 14

The contraction of liquids

Answer 14

Lower temperature in the molecules have less energy and move closer to each other this causes the volume of the liquid to decrease

Question 15

Can solids expand and contract a lot

Answer 15

Only a small amount because particles are held tightly by inter molecular forces around a fixed position

Question 16

Can gases expand and contract a lot

Answer 16

Quite large contraction and expansion because atoms held by weaker forces

Question 17

Can gases expand and contract a lot

Answer 17

Yes large amounts expansion increases pressure in the container because particles move more quickly and hit container with more force contraction reduce pressure in a container because particles move slower and hit container with less force

Question 18

How does a solid expand

Answer 18

When heated The particles in a solid move around quicker therefore hitting the container and other particles with a bigger force which pushes the particles further apart therefore expanding

Question 19

Where does conduction occur

Answer 19

In solids or metals

Question 20

Where does convection occur

Answer 20

Liquids and gases

Question 21

Where does radiation occur

Answer 21

From any hot object liquid or gas

Question 22

What is conduction

Answer 22

It is the heat transfer by means of faster pop molecules motion within the material without any shift of the material as a whole if one end of a metal rod is it higher temperature than energy will be transferred towards the colder end because the higher speed particles will collide with the slower ones with a net transfer of energy to the silver ones all metals are good conductors because of delocalised electrons

Question 23

What is convection

Answer 23

It is heat transferred by the motion of fluids such as air or water when they are heated fluid is cause to move away from the source of heat carrying energy with it convection above a hot surface occurs because hot air expands becomes less dense and rises hot water is less dense than cold water and rises causing convection currents which transfer energy

Question 24

What is radiation

Answer 24

It is the flow of heat from one place to another by means of electromagnetic waves the colour and shiny Ormat surface changes the amount of radiation omitted and absorbed

Question 25

What makes things sink or float

Answer 25

The density of the object
The weight of the object
If it has Air it

Question 25

What makes things sink or float

Answer 25

The density of the object
The weight of the object
If it has Air it

Question 26

What makes something float

Answer 26

Is the density of the object is less than the surrounding density

Question 27

What makes things sink

Answer 27

If the density of the object is greater than the surrounding density

Question 28

What are a few examples of convection

Answer 28

The mineshaft experiment – lighting a fire in a mine carbon dioxide goes up air goes down into the mine so miners can breathe
Lighting the paper – the density of the object is less than the surrounding density rises heat rises in air
The purple tube on one side as heated causing fluid to go up one side is colder causing fluid to sink therefore convection flow
Light bulb fan – when the fan is on top of the lightbulb heat rises therefore the particles push the fan round

Question 29

What are the two situations of radiation

Answer 29

A heat object admitting thermal radiation
An object absorbing thermal radiation

Question 30

Why is the matte black a better absorber of heat than the shiny silver

Answer 30

Because matte black is dull and absorbs the heat the shiny silver reflects the heat off of it

Question 31

Difference between evaporation and boiling

Answer 31

Evaporation happens at any time
Only happens surface of object
Causes a drop in the temperature
No bubbles
Opposite of condensation
Boiling happens at boiling point happens to rub the liquid doesn’t cause drop in temperature the air bubbles and is the opposite of condensation

Question 32

How do you calculate the specific heat capacity

Answer 32

= E
M(final temp-starting temp)

Question 33

What does SHC stand for

Answer 33

Specific heat capacity

Question 34

How do you calculate the energy in

Answer 34

Current volatagetime

Question 35

When heating water from an ice cube why does the temperature not increase at the melting point and boiling point of it

Answer 35

At the melting point it stops increasing in temperature because the energy is being used to break the intermolecular bonds between the solid to turn into a liquid then heats up till the boiling point and the same thing happens the energy is used to break the intermolecular forces between the liquid to turn it into a gas