What is the Law of Conservation of Mass?

• It states that matter cannot be created or destroyed.

• It states that energy cannot be created or destroyed.

• It states that matter can be created or destroyed.

• It states that sound can be created or destroyed.

Tags

NGSS.MS-PS1-5

What is the little number after an element in a chemical equation called.
Example: H₂

• Coefficient 
• Subscript
• Atom
• Equation

Which problem is balanced?
(Check ALL answers)

• PbO₂ + 2H₂
• SO₂ + H₂0 --> H₂SO₄
• 2Na + 2H₂O --> 2NaOH + H₂

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is the total number of atoms present in 5Na₃PO₄?

• 5

• 55

• 40

• 8

Tags

NGSS.MS-PS1-1

__ P₄ + __ O₂ -----> ____P₂O₅

• 1, 5, 2

• 2, 5, 7

• 2, 1, 5

• 5, 1, 2

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

___ Cr + ___O₂ -----> ____ Cr₂O₃

• 3, 2, 4

• 2, 3, 4

• 2,1, 5

• 4, 3, 2

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

___ AlBr₃ + ___ Cl₂ ----> ___ AlCl₃ +_{___} Br₂

• 2, 2, 3, 3

• 2, 3, 2, 3

• 2, 3, 3, 2

• 1, 2, 3, 4

Tags

NGSS.MS-PS1-5

___ NaClO₃ ----> ___ NaCl + ___ O₂

• 1, 3, 2

• 2,3,2

• 2, 2,3

• 3, 2, 2

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following equations are correctly balanced?

• 12CO₂ + H₂O ---> C₆H₁₂O₆ + O₂

• CO₂ + H₂O ---> 3C₆H₁₂O₆ + O₂

• CO₂ + 9H₂O ---> C₆H₁₂O₆ + O₂

• 6CO₂ + 6H₂O ---> C₆H₁₂O₆ + 6O₂

Tags

NGSS.MS-PS1-5

Balance this equation:

HgO ---> 2Hg + O₂

• It is balanced.

• 2HgO ---> 2Hg + O₂

• 2HgO ---> Hg + O₂

• HgO ---> Hg + 2O₂

Tags

NGSS.MS-PS1-5