Elements, Compounds, and Chemical Reactions

Which of the following is true for all chemical reactions?

• The total mass of the reactants equals the total mass of the products.

• The total mass of the products is greater than the total mass of the reactants.

• The total mass of the reactants increases.

• The total mass of the products is less than the total mass of the reactants.

Tags

NGSS.MS-PS1-5

When paper turns yellow-brown upon exposure to sunlight, what type of change is likely taking place?

• a physical change

• a chemical change

• neither a physical change nor a chemical change

• both a physical change and a chemical change

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What must occur for a change to be a chemical reaction?

• There must be a change in chemical properties.

• The change must involve a change in mass.

• The change must involve a change in volume.

• There must be a change in physical properties.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

All of the following changes to a metal are physical changes EXCEPT ____.

• rusting

• polishing

• melting

• bending

Which of the following represents a compound?

• H

• H₂O

• O-16

• H-3

Tags

NGSS.MS-PS1-1

Which action changes the identity of the substance referenced?

• running an electric current through copper

• melting gold

• breaking an ice cube

• corroding iron

Tags

NGSS.MS-PS1-5

What is one difference between a mixture and a compound?

• A mixture must be uniform in composition.

• A compound consists of more than one phase.

• A compound can only be separated into its components by chemical means.

• A mixture can only be separated into its components by chemical means.

A chemical change occurs when a piece of wood ____.

• is cut

• is split

• decays

• is painted

Tags

NGSS.MS-PS1-2

Which of the following is a chemical property?

• freezing point

• color

• hardness

• ability to react with oxygen

Which of the following is a chemical property of water at 4C?

• its color

• its state

• its ability to decompose into hydrogen and oxygen

• its temperature

Tags

NGSS.MS-PS1-1