States of matter
As a substance cools, what happens to the density of the molecules
They get denser
What is kinetic energy
The energy of motion/moving particles
If two objects have different temperatures, heat flows from the __________object to the _________object
warmer, colder
True or false, thermal energy is a type of energy that can be transferred between systems and objects
True
Metal and wood at the same temperature feel different to the touch. THis is because metals are________
good conductors (they can "take" more heat from your hand)
As a substance is cooled, the movement of molecules becomes_________________
slower
Most of the world uses this unit of temperature
Celsius
On a hot, sunny day, you should wear this color of clothing if you want to stay cool
Light colors, because they reflect more radiation
What is thermal equilibrium?
When objects reach a common temperature
Air is a very good (insulator or conductor?)
Insulator
What happens to the density of a substance when heat is added to it.
It gets less dense (expands)
Temperature is defined as_________
The measurement of average kinetic energy of the particles in a substance.
Polar bears have white colored fur to blend in with the snow, but their skin is black because_______
It helps them absorb radiation from the sun
when you hold an ice cube in your hand, the thermal energy flows from___________________
Your hand to the ice cube
Copper is a very good (insulator or conductor)
conductor
What happens to water when you put it in the freezer?
The freezer air (the colder substance) absorbs heat from the water (the warmer substance)
What happens at 0 degrees Kelvin?
The motion of atoms and molecules stops. (Absolute zero)
Ona sunny day, the upstairs rooms in a house are usually hotter than downstairs. THis is because______
Warm air rises
What type of thermal energy process is described here:
When you hold a metal coat hanger over a fire to roast marshmallows, the coat hanger gets too hot to handle
Conduction. The metal atoms vibrate and collide with nearby atoms, spreading up the coat hanger toward your hand.
If you put a plastic, wooden, and metal spoon in boiling water, which will have the warmest handle
metal
Ice cubes in the freezer get smaller over time because of the process where a solid goes straight to a gas. This is called______________
sublimation
You pick up a cold can of soda from the counter. The counter feels cold where the can was. This is because ______________
Some heat from the counter top has been transferred to the soda
After boiling an egg, you cool the egg by putting it in a bowl of cold water. Explain the egg's cooling process in terms of heat transfer
Heat energy is transferred from the egg to the water
A metal plate and a plastic plate are placed in a freezer all night. When you take them out in the morning and compare temperatures, what will you discover?
They are both the same
If you want to keep a can of soda cold, which is the best material to wrap it in:
Foil, wax paper, a wool sweater, or aluminum foil
Wool, because it traps air very well and air is an excellent insulator