Chemical Reactions and Equations

Which of the following describes a chemical reaction?

• A gas is given off when a liquid boils
• A new substance is formed with different properties
• A solid dissolves in a liquid
• a solid forms when a liquid freezes

Tags

NGSS.HS-PS1-2

Which of the following occurs when water freezes?

• a diatomic bond
• a chemical reaction
• a chemical bond
• a physical change

Tags

NGSS.HS-PS3-4

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

• energy change
• state change
• gas formation 
• solid formation

Tags

NGSS.MS-PS1-2

Which of the following is a product in this chemical reaction?
N + O₂ --> NO₂

• O₂
• NO₂
• N
• O

Tags

NGSS.MS-PS1-2

What happens in an exothermic reaction?

• energy is created
• energy is released
• energy is taken in
• energy is destroyed

Tags

NGSS.HS-PS1-4

What happens in an endothermic reaction?

• Energy is created
• Energy is destroyed
• Energy is released
• Energy is taken in

Tags

NGSS.HS-PS1-4

What happens to atoms in a chemical reaction?

• They are sometimes lost and never rearranged
• Theyare sometimes lost, gained or rearranged
• They are never lost or gained, just rearranged
• They are lost or gained, and never rearranged

Tags

NGSS.HS-PS1-7

Which of the following states the law of conservation of mass?

• Atoms are rearranged in a reaction and join new molecules
• Energy is neither created nor destroyed in a chemical reaction
• Mass cannot be created or destroyed in a chemical reaction
• Compounds form a new compound with different properties

Tags

NGSS.HS-PS1-7

Which statement is true according to the law of conservation of mass?

• The mass of the reactants > mass of the products
• The mass of the products > mass of the reactants
• Mass is destroyed
• Mass is not created

Tags

NGSS.HS-PS1-7

Which is the subscript

• a
• b
• c
• d

Tags

NGSS.HS-PS1-7