Physics Quiz 3

What are the 4 most common states of matter?

Solid, liquid, gas, plasma

Motion of a solid

Atoms vibrate in place. Slowest

Motion of a liquid

Increased vibration, Atoms can slip past one another. Bonds loosen. Slightly faster than solid

Motion of a gas

Atoms begin to move faster and in random directions. Bonds break. Fast

motion of plasma

Atoms are so energized that electrons pop off the nucleus. Fastest

How do we measure the motion of these atoms?

**Temperature** - The measurement of the average kinetic energy (energy of motion) of the atoms in a substance.

What units do we use for motion measurement?

Fahrenheit (℉), degrees Celsius (℃), Kelvin (K)

What do we call the absence of atomic motion?

“**Absolute Zero**” means “0 K”, and is defined as the temperature at which molecules are moving as little as they possibly can.

As atoms move around, they transfer some of their motion/energy to other atoms. **What do we call this transfer of energy?**

**Heat**: Energy transferred from one object to another as a result of a difference in temperature.

As atoms move around, they transfer some of their motion/energy to other atoms. **In which direction does it flow?**

The transfer of thermal energy (heat) always moves from areas of HIGH concentration to areas of LOW concentration (**HEAT LEAVES**)

Explain the process of a solid turning into a liquid and then into a gas (or the reverse) by focusing on the movement, spacing of atoms/molecules, and bonds between atoms/molecules within the substance and whether energy is being added or removed.

• According to Kinetic Molecular Theory in order for a substance to change from a gas to a liquid energy must be removed causing the atoms to slow down and get closer together.

• Adding internal energy increases molecular motion causing molecules to spread apart and bonds to weaken.