Chemical Formulas and Equations

This appears on the left side of a chemical formula, and represents how many molecules there are.

• an atom
• the subscript
• a molecule
• the coefficient

Tags

NGSS.MS-PS1-1

How many hydrogen atoms are in this chemical formula?

• 4 hydrogen atoms
• 1 hydrogen atom
• 2 hydrogen atoms
• 3 hydrogen atoms

Tags

NGSS.MS-PS1-1

How many oxygen atoms are in this chemical formula?

• 7 oxygen atoms
• 4 oxygen atoms
• 3 oxygen atoms
• 1 oxygen atom

Tags

NGSS.MS-PS1-1

How many oxygen atoms are in this chemical formula?

• 6 oxygen atoms
• 2 oxygen atoms
• 3 oxygen atoms
• 4 oxygen atoms

Tags

NGSS.MS-PS1-1

Is this balanced?

2HgO → 2Hg + O₂

• Yes

• No, Hg is not balanced.

• No, O is not balanced.

Tags

NGSS.MS-PS1-5

Is this balanced?

2Al + O₂ → Al₂O₃

• Yes

• No, O is not balanced.

• No, Al is not balanced.

Tags

NGSS.MS-PS1-5

Law of conservation of matter states that ____.

• Matter can be created
• Matter can be destroyed
• Matter can neither be created nor destroyed
• Matter does not change

Tags

NGSS.MS-PS1-5

The total amount of matter (atoms) before and after a chemical reaction (change), remains the same.

• True
• False

Tags

NGSS.MS-PS1-5

What will weigh more when a chemical change is complete? The reactants before the chemical reaction, or the product after the reaction is complete?

• They both will weigh the same.
• The product always weighs more than the reactant.
• The reactant will weigh more than the product.
• They both will lose mass after the reaction.

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

If four hydrogen atoms react with two hydrogen atoms, how many atoms will be in the product?

• 6
• 4
• 8
• 2

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2