Simple Chemical Reactions

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

• F

• G

• H

• J

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Balance this equation:
 2Li + Cl₂ -> LiCl

• 2Li + Cl₂ -> 4LiCl2

• 2Li + Cl₂ -> LiCl₂

• 2Li + Cl₂ -> 2LiCl

Tags

NGSS.MS-PS1-5

Which number should go in the blank?
_ H₂ + O₂ -> 2 H₂O

• 1

• 2

• 3

• 0

Tags

NGSS.MS-PS1-5

Balance this equation:

__ Al + __ HCl → __ H₂ + __ AlCl₃

• 2, 6, 3, 2

• it is already balanced

• 4, 12, 3, 4

• 2, 1, 4, 5

Tags

NGSS.MS-PS1-5

the starting materials in a chemical reaction

• Products

• Reactants

• Starters

• Enders

a substance that is formed as the result of a chemical reaction

• Product 

• Reactant

• Starters

• Enders

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following examples shows that a chemical reaction has occurred? 

• A rock breaks into smaller pieces when it is struck with a hammer.

• Rust forms on a hammer that has been left outside to long. 

• A cup of water turns pink when a few drops of red food coloring are added. 

• A solid is formed when heat is removed from a sample of water. 

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A student places a piece of a potato into a container of hydrogen peroxide. One observation the student makes is that bubbles form around the potato. The presence of bubbles might indicate the formation of a new substance because bubbles - 

• could show that a gas is forming

• always rise to the top of a liquid. 

• are almost always perfectly spherical.

• usually burst after a few minutes.

Tags

NGSS.MS-PS1-2

Which of the following is an example that includes evidence of a chemical reaction?

• A sample of zinc is placed in water and it settles to the bottom

• A solid block of ice is heated and it completely melts into a liquid. 

• Sugar that is burned gives off an odor and turns brown and then black.

• A tomato is placed into a blender and chopped up into smaller pieces.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Evidence of a chemical reactions is anything that shows - 

• a new substance has formed

• a solid dissolved in a liquid

• interaction between 2 gases

• a change in the state of matter

Tags

NGSS.MS-PS1-2