Signs of Chemical Reactions

You have 2 chemicals, CHEMICAL A and CHEMICAL B. They are both liquids. When you combine them you notice some crystals starting to form within them. Did a chemical reaction occur?

• Yes

• No

Tags

NGSS.MS-PS1-2

You have a large glass of water and you stir salt into it until all the salt completely dissolves. Is this a chemical reaction?

• Yes

• No

Tags

NGSS.MS-PS1-2

A substance that is formed as the result of a chemical reaction is a __________________

• Product

• Reactant

• Starters

• Enders

Tags

NGSS.MS-PS1-2

A change in the shape of an object is an example of _________________.

• a chemical change

• energy

• an endothermic change

• a physical change

Which one shows that a chemical reaction has occurred?

• dissolving

• melting

• formation of a gas

• bending

Tags

NGSS.MS-PS1-2

In a ___________change, a substance changes into a different substance.

• Physical
• Chemical

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is the BEST definition of a chemical reaction?

• A change in matter that produces one or more NEW substances

• When two things combine and EXPLODE.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

the starting materials in a chemical reaction

• Products
• Reactants
• Starters
• Enders

A teacher is demonstrating physical and chemical changes to her class. Which action should she use to demonstrate a chemical change?

• cutting a piece of paper
• folding a piece of paper
• tearing a piece of paper
• burning a piece of paper

Tags

NGSS.MS-PS1-2

Which of the following describes a precipitate?

• a liquid forms when a block of metal is heated
• a solid forms when one liquid is poured into another
• a gas forms when a solid is placed in a liquid
• bubbles form when an acid is poured on a rock

Tags

NGSS.MS-PS1-2