Lesson 1 Particles in Motion

When talking about particles moving, if the particles are moving from one area of concentration and spread out to areas of lower concentration this is known as ___________.

• kinetic energy
• random motion
• diffusion
• thermal expansion

When you decrease the temperature, the average __________________ decreases.

• chemical energy
• potential energy
• kinetic energy
• radiation energy

The unit for measuring energy is ________________.

• Joules
• Kelvin
• Fahrenheit
• Newtons

The study of heat is known as ___________.

• temperature
• the law of thermal expansion
• thermal contraction
• thermodynamics

When measuring the average kinetic energy of an objects particles, you are measuring its _________.

• joules
• temperature
• Kelvin
• potential energy

A balloon full of air is placed into a freezer. When you remove the balloon an hour later, you observe that the balloon is noticeably less full of air. You observed ____________.

• thermal contraction
• thermal expansion
• temperature
• diffusion

A metal ball that was pulled from a slot in a bearing to be cleaned. It was heated with a propane torch for 30 minutes. When trying to put the metal ball back, it wouldn't go back into the bearing because the ball seemed bigger than the slot. You observed ________.

• thermal contraction
• temperature
• thermal expansion
• thermodynamics

Which of the following statements about the particles in a material is true?

• The average kinetic energy of the particles decreases as the temperature increases.
• The average kinetic energy of the particles in a substance never changes.
• The average kinetic energy of the particles increases as the temperature increases.
• There is no relationship between kinetic energy and temperature.

Kinetic energy is the energy of __________.

• temperature
• gravity
• potential
• motion