Law of Conservation of Mass

What is the Law of Conservation of mass?

• Mass is created in a chemical reaction
• Mass is created in a physical change
• New chemicals formed from a chemical reaction have a larger overall mass than the original reactants
• Mass is never created or destroyed

Tags

NGSS.MS-PS1-5

In a reaction A + B ----> C,  reactant A has 5g and product  C has 9g. How many grams does reactant B should have? 

• 4g
• 5g
• 9g
• 14g

Tags

NGSS.MS-PS1-5

The number in front of a compound or element is a 

• Subscript
• Coefficient
• Superscript
• Charge

The number to the lower side of an element is a 

• Subscript
• Superscript
• Coefficient
• Charge

Tags

NGSS.MS-PS1-1

Which of the following are Subscripts in this Chemical Formula: 3Fe₂O₄

• 3,4

• 3,2

• 2,4

• 6

Tags

NGSS.MS-PS1-1

The coefficient in  3H₂O is

• 6
• 2
• 3
• 5

Tags

NGSS.MS-PS1-1

The Coefficient (3) in the Chemical Formula, 3H₂O, tells you how many _____________ there are.

• Atoms of Hydrogen

• Atoms of Oxygen

• Atoms of Water

• Molecules of Water

Tags

NGSS.MS-PS1-1

The Subscript (2) in the Chemical Formula, 3H₂O, tells you how many _____________ there are.

• Atoms of Hydrogen

• Atoms of Oxygen

• Atoms of Water

• Molecules of Water

Tags

NGSS.MS-PS1-1

How many nitrogen atoms does NH₃ have?

• 1
• 2
• 3
• 4

Tags

NGSS.MS-PS1-1

Which Chemical Equation is Balanced?

• CH₄+O₂------CO₂+2H₂O

• H₂+O₂-----2H₂O₄

• 4Al+3O₂-----2Al₂O₃

Tags

NGSS.MS-PS1-5