Chemical Equations

How many oxygen atoms are present in the following chemical formula?

4Ca(OH)₂

• 4

• 6

• 8

• 1

How many atoms of pretend element E are there in this silly chemical formula?

2E₂Fg₃Hi₄

• 4

• 2

• 1

• 3

Which of the following can be broken apart in a chemical reaction? 

• Noble gases
• Molecules and compounds
• only molecules
• only compounds 

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

Determine what number goes in the blank to balance the chemical equation below.

2KI + ____Cl₂ → 2KCl + I₂

• 1

• 2

• 3

• 4

What numerical coefficient should go in the blank space below to balance the chemical equation?

2Al +____ HCl → 2AlCl₃ + 3H2

• 2

• 4

• 3

• 6

The substances listed on the right side of a chemical equation are the

• Yields
• Reactants
• Products
• Precipitates

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

CaCO₃ represents a chemical

• Symbol
• Formula
• Subscript
• Reaction

Tags

NGSS.MS-PS1-1

The substances listed on the left side of a chemical equation are the

• Products
• Coefficients
• Precipitates
• Reactants

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

In chemical reactions, what does the principle of conservation of mass/matter mean?

• Matter is not created or destroyed.

• The total mass of the reactants is greater than the total mass of the products.

• The total mass of the reactants is less than the total mass of the products.

• Matter is not changed.

Identify the reactant(s) and product(s) of the reaction.

• All three are reactants and none are products.
• Hydrogen and water are the reactants, and oxygen is the product.
• Water and oxygen are the reactants, and hydrogen is the product.
• Hydrogen and oxygen are the reactants, and water is the product.