Chemistry Part I

Which of the following are signs of a chemical reaction?

• Formation of a gas

• A change in temperature

• A change in color

• an ice cube melting

Tags

NGSS.MS-PS1-2

The change of a substance where NO new substances are formed

• catalyst

• chemical change

• physical change

• surface area

When a chemical reaction occurs...

• New substances are formed

• Molecules and atoms disappear

• Molecules and atoms are destroyed

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The substances that are combined or mixed to start a chemical reaction are called .............?

• Molecules

• Reactants

• products

• catalysts

Tags

NGSS.MS-PS1-1

A substance that has been diluted has had what added to it?

• temperature

• water

• molecules

• energy

In a chemical reaction, the number of atoms in the reactants and the products...

• Must be the same

• Must be different

Tags

NGSS.MS-PS1-5

After a chemical reaction, new substances are formed called...........?

• products

• reactants

• subscripts

• formulas

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What gas in the air causes fire to burn, iron to rust and food to spoil or decay?

• Nitrogen

• Hydrogen

• Oxygen

• Carbon Dioxide

When baking soda and vinegar are mixed, a chemical reaction occurs and the temperature gets cold. What type of reaction is this?

• Exothermic reaction

• Endothermic reaction

• External Reaction

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

What type of chemical reaction gives off heat?

• Exothermic

• Endothermic