Counting Atoms and Chemical Reactions

How many Hydrogen atoms are in 4H₂O?

• 6
• 8
• 2
• 4

How many Oxygen atoms are in H₂O?

• 1
• 2
• 0
• 4

How many Magnesium atoms are in 10MgCl₂?

• 10
• 5
• 20
• 12

How many TOTAL atoms are there in:
H₂SO₄

• 6
• 5
• 7
• 3

How many elements are in C₆H₁₂O₆?

• 1
• 2
• 3
• 4

How many Sodium atoms are in 6NaCl?

• 1
• 12
• 6

How many atoms of Hydrogen are in this molecule?

• 1
• 2
• 3
• 4

Element or Compound?
C₂H₈O 

• Element
• Letters
• Numbers
• Compound

A subscript is the small number to the lower left of a(n) ________ that tells the number of _______ of that element.

• element symbol; atoms
• atom; element symbol
• subscript; protons
• compound; elements

Which is the correct formula for:
three hydrogen  atoms (H)
one sulfur atom (S)
four oxygen atoms (O)

• H₃SO₄
• HSO₄
• H₄S₃O
• H₂O