Counting Atoms and Conservation of Mass

How many Hydrogen are in 4H₂O?

• 6
• 8
• 2
• 4

Tags

NGSS.MS-PS1-1

How many Magnesium are in 10MgCl₂?

• 10
• 5
• 20

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

• ------>
• 2H₂O
• 2H₂+ O₂

Tags

NGSS.MS-PS1-1

How many O's are in Al₂(SO₄)₃

• 4
• 12
• 7
• 24

Number of N in (NH₄)₂CrO₄

• 1
• 2
• 8
• 16

What is a coefficient?

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

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

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

• Coefficient 
• Subscript
• Atom
• Equation

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

• Coefficient
• Products
• Reactants
• Subscript