Counting Atoms and Balancing Chemical Equations

How many Hydrogen are in 4H₂O?

• 6
• 8
• 2
• 4

Tags

NGSS.MS-PS1-1

How many Magnesium are in 10MgCl₂?

• 10
• 5
• 20

Tags

NGSS.MS-PS1-1

2H₂ + O₂ ----> 2H₂O What is the product?

• ------>
• 2H₂O
• 2H₂+ O₂

Tags

NGSS.MS-PS1-2

How many O's are in Al₂(SO₄)₃

• 4
• 12
• 7
• 24

Tags

NGSS.MS-PS1-1

What is a coefficient?

• The small number on the right of the chemical symbol.
• The large number to the left of a formula.

Tags

NGSS.MS-PS1-5

Is this equation balanced?

• yes
• no
• Not enough information

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

How many atoms of Carbon are in the compound C₂H₈O ?

• 8
• 2
• 1
• 11

Tags

NGSS.MS-PS1-1

The law of conservation of matter states that

• chemical reactions change matter.
• in chemical reactions, the identity of reactants and products is conserved.
• atoms are neither created nor destroyed in chemical reactions.
• a chemical equation must be balanced.

Tags

NGSS.MS-PS1-5

Why is the following chemical equation not balanced?
H_{2 +} O₂ --> H₂O

• each side of the equation has a different number of oxygen atoms
• each side of the equation has a different number of hydrogen atoms
• each side has the same mass

Tags

NGSS.MS-PS1-5

Is the following equation balanced or unbalanced?
Fe + S --> FeS

• balanced
• unbalanced

Tags

NGSS.MS-PS1-5