Chemical Reactions

Which of the following models best demonstrates a balanced chemical equation?

• F
• G
• H
• J

Tags

NGSS.MS-PS1-5

Coal contains carbon and other elements. Carbon dioxide forms when coal burns in the presence of oxygen. Which of these is the best evidence that a chemical reaction occurs when coal burns?

• The shape of the coal changes
• Oxygen is present
• A new substance is produced
• Coal is made up of more than one element

Tags

NGSS.MS-PS1-2

According to the law of conservation of mass...

• sometimes atoms are lost
• sometimes atoms are gained
• atoms are never lost nor gained
• atoms are lost and gained

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The force that holds 2 atoms together is called a ________________.

• Chemical Reaction
• Chemical Bond
• Diatomic Chemical
• Glue

Tags

NGSS.HS-PS1-4

Which of the following is a chemical change?

• water freezes to form ice
• sugar dissolves in water
• gasoline burns in a car engine
• a piece of metal expands when it is heated

Tags

NGSS.MS-PS1-2

In the reaction methane + oxygen turns into carbon dioxide + water, the methane and oxygen are called _______________.

• reactants
• products
• neutrals
• energizers

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

• a chemical change
• energy
• an endothermic change
• a physical change

What type of change occurs when a new substance is formed that has different properties from the original substances?

• chemical change
• nuclear change
• physical change
• mutation

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Increasing the concentration of a reactant in a chemical reaction will _____________.

• decrease the rate of the reaction
• stop the reaction from happening
• increase the rate of the reaction
• have no effect on the rate of the reacion

Tags

NGSS.HS-PS1-5

Which of the following represents a chemical change?

• cutting a piece of paper with scissors
• cooling a mixture of air and kerosene vapor to obtain liquid kerosene
• burning a piece of notebook paper in the presence of oxygen
• heating water over a flame to its boiling point

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5