Chemical Reactions Pre-Assessment

True or false? Chemical reactions are easily reversible

• True

• False

Tags

NGSS.HS-PS1-6

The diagram above shows the repeating groups of atoms that make up two samples. Both samples are red powdery solids at room temperature. Will the other properties of the two samples be the same or different? (Examples of properties are smell, color, and the temperature at which a substance melts.)

• The other properties will be different because there are more repeating groups of atoms in Sample 1.

• The other properties will be the same because both samples are red at room temperature.

• The other properties will be the same because both samples are powdery solids at room temperature.

• The other properties will be same because the repeating groups of atoms that make up the two samples are the same.

Tags

NGSS.MS-PS1-1

True or false: A change in state is a chemical reaction

• True - something melting would be an example of a chemical reaction

• False - a change in state is a physical change

Tags

NGSS.MS-PS1-4

A material that burns to transfer energy is called a...

• compound

• wood

• fuel

• petrol

What does a fuel need in order to burn?

• fuel

• electricity

• oxygen

• hydrogen

Which is NOT an example of something you could observe that would suggest a chemical reaction is taking place?

• melting

• fizzing

• smells

• temperature change

Tags

NGSS.MS-PS1-2

Can one substance change into another substance? (read carefully)

• No, because things can mix, but they can't change into new things

• Yes, because new atoms can be created

• No, because atoms can not be destroyed

• Yes, because atoms can be rearranged.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A scientist mixed two samples together: a colorless liquid that melts at 12°C and a yellow solid that melts at 390°C. She analyzed the results and found two ending substances. One of the ending substances was a gray solid. This ending substance is made up of the repeating group of atoms shown above. Which of the diagrams to the left shows the repeating groups of atoms that make up the samples the scientist mixed together?

• 
• 
• 
• 

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is a reactant?

• Something that actanats again

• A starting substance before a chemical reaction

• A potato

• What happens when you have the reflexes of a ninja and can react quickly.

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

Samira watched a demonstration in which a scientist combined two substances in a sealed container and analyzed the results. The ending substances did not look the same as the starting substances.

Samira was given a diagram with the repeating groups of atoms that make up the starting substances, plus information about the properties of the starting and ending substances. She created a model of the repeating groups of atoms that might make up the two ending substances.

• Samira's model correctly demonstrates how the properties changed with the rearrangement of the atoms. However not all atoms are accounted for. There is a missing reactant.

• Samira's model is correct because the properties are different and the atoms are rearranged.

• Samira's model is incorrect because not all atoms are accounted for

• Samira's model correctly demonstrates how the properties changed with the rearrangement of the atoms. However not all atoms are accounted for. There is a missing product.

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5