Counting Atoms

What does the subscript in a chemical formula tell you?

• How many molecules are present

• How many atoms are present

• How many compounds are present

• How many neutrons are present

Which chemical formula correctly displays 1 atom of nickel and 2 atoms of Fluorine?

• niF2

• NIF₂

• Ni₁F₂

• NiF₂

Tags

NGSS.MS-PS1-1

How many Hydrogen are in 4H₂O?

• 6

• 8

• 2

• 4

Tags

NGSS.MS-PS1-1

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

• ------>
• 2H₂O
• 2H₂+ O₂

Tags

NGSS.MS-PS1-2

2H₂ + O₂ --------> 2H₂O What  are the reactants?

• ----->
• 2H₂O
• 2H₂ +O₂

How many Sodium (Na) are in 6NaCl?

• 1

• 12

• 6

Tags

NGSS.MS-PS1-1

How many atoms are in the element Carbon in this compound?
H₂C₃O₄N₅

• 2
• 3
• 4
• 5

Tags

NGSS.MS-PS1-1

What is a coefficient?

• The small numbers that MULTIPLY the elements in the compound after together.

• The large number to the left of a formula that MULTIPLIES the elements in the compound after.

• The large number to the left of a formula that ADDS the elements in the compound after.

• The small numbers that ADD the elements in the compound after together.

Tags

NGSS.MS-PS1-5

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

How many O's are in Al₂(SO₄)₃

• 4
• 12
• 7
• 24

Tags

NGSS.MS-PS1-1