Chemical Reactions Review

_______________ is an example of both a color change and new substance produced from a chemical change with oxygen and metal.

• shredded paper
• rust (iron oxide)
• wood chips
• melted wax

A candle wick burning is an example of a _________________________

• physical reaction
• condensation
• neutrons
• chemical reaction

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

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

• Physical
• Chemical

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of these is NOT a sign that a chemical change has occurred? 

• Change in shape.
• An unexpected color change
• A temperature change
• The formation of a precipitate

Tags

NGSS.MS-PS1-2

You know that a chemical reaction has occurred if

• there is a precipitate (new solid)

• there is a color change.

• there is a temperature change.

• All of these answers are evidence.

Tags

NGSS.MS-PS1-2

When a candle melts, it is a ___________________  change.

• chemical
• physical
• transparent
• undefined

What indicates a chemical reaction occurred?

• Heat or Light is released
  heat or light is produced
• gas (bubbles) produced
• color change
• all of the above

Tags

NGSS.MS-PS1-2

A(an) ______ is the number that appears before a formula in a chemical equation.

• subscript

• coefficient

• ratio

• denominator

Tags

NGSS.MS-PS1-5

1. How is a chemical change different from a physical change?

• there is no difference

• a physical change creates a new substance

• a chemical change creates a new substance

A chemical change is different than a physical change because in a chemical change

• chemicals are used

• molecules do not physically touch

• a new substance is formed and in a physical no new substance is formed

• the change can be seen but in a physical change it cannot

Tags

NGSS.MS-PS1-2