Front

What is the direction of heat transfer?

Back

Heat always travels from warm to cool.

Front

In a chemical reaction, if you start with 23 atoms, how many atoms will remain after the reaction?

Back

You would expect to have 23 atoms remaining.

Front

What is the product of the reaction 2H₂ + O₂ → ?

Back

The product is 2H₂O.

Front

Why do a hot pan and a cold counter reach the same temperature over time?

Back

Because thermal energy will be transferred from the pan to its surroundings.

Front

What are fizzing, foaming, and burning examples of?

Back

They are examples of a chemical change.

Front

Define thermal energy.

Back

Thermal energy is the energy that comes from the temperature of matter.

Front

What is a chemical change?

Back

A chemical change is a process where substances combine or break apart to form new substances.

Front

What is the law of conservation of mass?

Back

The law states that mass is neither created nor destroyed in a chemical reaction.

Front

What is an example of a physical change?

Back

Melting ice is an example of a physical change.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance made of one type of atom, while a compound is made of two or more different types of atoms chemically bonded together.