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Thursday 2/27 - Chemical Reactions Review

Last updated 14 days ago
19 questions
Did a Chemical Reaction Happen?

Did a Chemical Reaction Happen?

Chemical Reaction - Substances are mixed and at least one new substance with different properties (with different molecules) is formed.

Directions:
  • Analyze each diagram. Look carefully at both the observable scale and the nanoscale.
  • Think about whether there is evidence that a chemical reaction happened.
  • Answer the question below each diagram.
Ice Melting:


1

Ice Melting: Is there evidence of a chemical reaction?

1

Is this a chemical reaction? Explain why.

Chemical Reaction - Substances are mixed and at least one new substance with different properties is formed.

Candles burn:



3

Candles burn: Is there evidence of a chemical reaction? Select all that apply.

1

Is this a chemical reaction? Explain why.

Chemical Reaction - Substances are mixed and at least one new substance with different properties is formed.

Baking Soda and Vinegar Mixing:


1

Baking Soda and Vinegar Mixing: Is there evidence of a chemical reaction?

1

Is this a chemical reaction? Explain why.

Chemical Reaction - Substances are mixed and at least one new substance with different properties is formed.

Chemical Reactions

What Happens Before a Chemical Reaction?

Ca + 2H2O → Ca(OH)2 + H2

Before After

1

How many Ca (calcium) atoms are there before the reaction?

1

How many O (oxygen) atoms are there before the reaction?

1

How many H (hydrogen) atoms are there before the reaction?

What Happens After a Chemical Reaction?

Ca + 2H2O → Ca(OH)2 + H2

Before After

1

How many Ca (calcium) atoms are there after the reaction?

1

How many O (oxygen) atoms are there after the reaction?

1

How many H (hydrogen) atoms are there after the reaction?

Ca + 2H2O → Ca(OH)2 + H2

Before After

1

What do you notice about the number of atoms before and after the chemical reaction?

1

Did any atoms created or destroyed (appear or disappear)?

1

Would the weight of the substances change before and after the chemical reaction?

1

What happens to the atoms and molecules before and after a chemical reaction?

1

Is this a chemical reaction? Explain why and explain what happened to the atoms.

Chemical Reaction - Substances are mixed and at least one new substance with different properties is formed.

1

The picture below is the beginning of a chemical reaction.


Choose the correct model after chemical reaction.

0

Explain why you chose that answer for 17.