Counting Atoms and Chemical Equations

What are the smaller numbers that you CANNOT change in a chemical equation? 

• Coefficient

• Products

• Reactants

• Subscript

How many HCl molecules do you need to balance this equation? 
Mg +  __HCl --->  MgCl₂ + H₂

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5

What coefficient should be used to make the following equation balanced?
N₂+O₂--> _NO 

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5

How many Sodium (Na) are in 6NaCl?

• 1

• 12

• 6

Tags

NGSS.MS-PS1-1

Is this equation balanced?

• yes

• no

• Not enough information

Tags

NGSS.MS-PS1-5

Balance this equation:
MgCl₂ --> Mg₄+ Cl₂

• It's already balanced.

• 4MgCl₂ --> Mg₄+ 4Cl₂

• 4MgCl₂ --> Mg₄+ 5Cl₂

Tags

NGSS.MS-PS1-5

Balance this equation
_N₂ + _H₂ --> _NH₃

• 1,2,3

• 1,3,2

• 1,1,2

• 2,1,1

Tags

NGSS.MS-PS1-5

How many TOTAL atoms are in the following chemical formula?
3H₂O

• 7

• 6

• 9

• 8

Tags

NGSS.MS-PS1-1

At the end of chemical reactions, what is the total mass of the reactants compared to the total mass of the products?

• the product is doubled

• the product is half the mass of the reactants

• the mass is the same

• the mass changes depending on the reaction

Tags

NGSS.MS-PS1-5

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

• F

• G

• H

• J

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5