Phases of Matter and Heat Transfer

Matter

• Video on the discovery of the nucleus

Phases of Matter

• There are 5 phases of matter

• Phase changes are controlled by the energy of the material

• Can anyone name the 5 phases?

Phases of Matter

• There are 5 phases of matter

• Phase changes are controlled by the energy of the material

• Can anyone name the 5 phases?

Phases of Matter

• Video on plasma and BE condensate

Temperature

• Temperature – A quantity that tells you how hot or cold a material is compared to a standard.

• We usually measure temperature in Fahrenheit (F), and Celsius (C). For our class we will use Kelvin (K)

Temperature

Kelvin = Celsius + 273

Celsius = 9/5 (Fahrenheit – 32)

Heat Transfer

• Heat – The energy that transfers from one object to another because of a temperature difference.

• Heat flows from a higher temperature substance, to a lower temperature substance

Heat Transfer

• We measure heat in the unit known as calories

• A calorie is defined as the amount of heat to change 1 gram of water 1 C°

• We say “cal” for short. 1000 calories is a kilocalorie

Heat Transfer

• Materials have a quantity known as specific heat capacity.

• Specific heat capacity is how much heat a material can hold per mass and degree Celsius.

• We use the variable “c” to define specific heat.

• Units are calories/(grams °C)

Heat Transfer

• The higher the specific heat capacity, the more heat a material can hold.

• Material with lower specific heat capacities get hotter quicker, like Iron or sand.

• Water has a high specific heat capacity = 1cal/g°C

Heat Transfer

• The quantity of heat, which will be defined with the variable Q, can be found with the following equation

Q = mcΔT

• Heat = mass x specific heat capacity x Temperature change (Celsius)

Heat Transfer

• You can calculate the heat required to change the phase of a material from one phase to another

Q = mLHeat = mass x latent heat

• The units of latent heat are calories/gram. Every phase change has a specific latent heat. Heat of fusion involves interchanging between a solid and liquid, and heat of vaporization involves changing between a liquid and a gas.

Heat Transfer

• Try these problems