Chemical Reactions

True or False
In a chemical reaction, no new atoms are created, and no atoms are destroyed. 

• true
• false

Tags

NGSS.MS-PS1-5

A chemical change is different than a physical change because in a chemical change

• Chemicals are used
• Molecules do not physically touch
• A new substance is formed and in a physical change no new substance is formed
• The change can be seen but in a physical change it cannot

Tags

NGSS.MS-PS1-2

The left side of the equation below is called

• Products
• Reactants

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

The right side of the equation below is called the

• products
• reactants

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which statement is not a description of a chemical reaction?

• A solid is dropped into a beaker of liquid and a gas is released.
• Two liquids are mixed in a beaker and a solid forms at the bottom of the beaker.
• A solid is dropped into a beaker of liquid and an explosion occurs.
• A liquid is heated in the sun and half of it evaporates.

Tags

NGSS.MS-PS1-2

A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction.

• Coefficient
• reactant
• subscript
• product 

Tags

NGSS.MS-PS1-5

Which of the following is NOT a sign of a chemical reaction? 

• Color changes
• Cutting into fourths
• Light is produced
• Gas is formed

Tags

NGSS.MS-PS1-2

In a chemical reaction

• The atoms of the reactants always stay together to form the products
• The atoms of the reactants unbond, rearrange, and then rebond to form the products
• New atoms are formed which combine to make the products
• Some atoms disappear while others multiply to form the products

Tags

NGSS.MS-PS1-5

Which of the following answers will balance the equation below?
__K + __Br₂ --> __KBr

• 2, 1, 1
• 2, 3, 2
• 2, 1, 2
• 1, 2, 3

Tags

NGSS.MS-PS1-5

If the reactants on the left side of a chemical equation are C₃H₈ + 5O₂, the products in a balanced equation could be

• 4CO₂ + 3H₂O
• 3CO₂ + 4H₂O
• 2CO₂ + 3H₂O
• 3CO + 4H₂O

Tags

NGSS.MS-PS1-5