As liquids are heated, the molecules that make up the liquids move faster.

Regular ovens use hot air to heat food. When you turn on an oven, you can sometimes see the coils get hot, or you can see a ______________.

The __________ as molecules in the air collide with a hot surface. Hot air in the oven then heats the food.

Fast- moving molecules in the air

collide with the molecules on the surface of the food. The collisions make molecules in the food

move faster.

Remember that the faster the molecules move, the more energy they have. As the food molecules get more energy from the hot air molecules around them, the food gets ______________.

It takes ___________ for the food to become warm all the way to the center.

Microwave ovens do not use hot air to heat food. Instead, they work by heating food with a form of light that your eyes cannot detect, called _______________.

When you turn on a _____________ oven, a device in the oven makes microwaves. The microwaves reflect off the walls of the oven and move in the oven in all directions.

Microwaves, like all light, are a form of __________________. As microwaves pass through food, they are absorbed by molecules in the food.

Their energy gets transferred to the food molecules, causing them to move faster. For example, microwaves make the ______________________ molecules in food move back and forth about a million times a second.

When the molecules in the food move faster, the food

heats because the molecules in the food have more ______________.

Microwave ovens heat food faster than regular ovens because microwaves can make the __________________in the food move faster all at once.

You do not have to wait for each food molecule

to move faster one by one, starting from the ones on the outside, like in regular ovens. This is why it takes less time to ____________ something in a microwave oven.

models of solids, liquids, and gases to show that

adding or removing thermal energy increases or decreases kinetic energy of the particles until a change of state occurs

Pure substances can include water, carbon dioxide, and helium.

What plant helped humans discover and make chocolate?

To separate a mixture of salt and water what separation tool/method is used?

Microwave energy penetrates from the outside in.

A liquid can also change to a gas without boiling. This process is called _____________.

How quickly a changes occurs at different temperatures is called the _____________.

____________________________ are changes to matter that do not affect the type of matter.

___________________________ result in a change in the identity of matter.

Most matter expands when temperature goes ________________ and contracts when temperature goes _________________.

Water is special it _____________________ when it freezes, making ice less dense than liquid water.

Physical changes to matter can happen _______________________ or ___________________________ at different temperatures

Name the change: Slicing a loaf of bread.

Name the change: Rust on a car.

Name the change: Rotten banana

Name the change: Water evaporates.

Name the change: Cracking eggs.

Name the change: Eating and digesting apples.