Counting Atoms in Chemical Formulas

How many atoms of Carbon, Fluorine, and Chlorine are in the formula 4CF₂Cl₂?

• C = 4, F = 8, Cl = 8

• C = 4, F = 6, Cl = 6

• C = 2, F = 8, Cl = 4

• C = 4, F = 10, Cl = 8

Tags

NGSS.MS-PS1-1

What is the chemical formula for a compound with 3 Carbon, 5 Hydrogen, 3 Nitrogen, and 9 Oxygen atoms?

• C₃H₅(NO₃)₃

• C₃H₇(NO₂)₃

• C₃H₅(N₂O₃)₃

• C₃H₅(NO₂)₃

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

What is the significance of the number in front of a chemical formula?

• It indicates how many molecules of that compound are present.

• It represents the atomic mass of the compound.

• It shows the temperature at which the compound is stable.

• It indicates the color of the compound.

If a chemical formula has no subscript next to an element, what does that mean?

• It means there is one atom of that element.

• It means there are two atoms of that element.

• It means the element is not present in the compound.

• It means the element is in a gaseous state.

Tags

NGSS.MS-PS1-1

What is a coefficient in a chemical formula?

• A number written in front of a chemical formula.

• A symbol representing an element.

• A type of chemical bond.

• The total number of atoms in a molecule.

Tags

NGSS.MS-PS1-5

What is the purpose of subscripts in chemical formulas?

• To indicate the number of atoms of each element in a molecule.

• To represent the charge of an ion in a compound.

• To show the state of matter of a substance.

• To indicate the temperature at which a reaction occurs.

Tags

NGSS.MS-PS1-1

What is the difference between a coefficient and a subscript?

• A coefficient indicates the number of atoms of a specific element, while a subscript multiplies the entire formula.

• A coefficient multiplies the entire formula, while a subscript indicates the number of atoms of a specific element.

• A coefficient is used only in chemical equations, while a subscript is used in mathematical equations.

• A coefficient and a subscript are the same and can be used interchangeably.

What happens to the number of atoms when a coefficient is applied to a chemical formula?

• The coefficient has no effect on the number of atoms.

• The coefficient multiplies the number of each type of atom in the formula.

• The coefficient only affects the total mass of the compound.

• The coefficient changes the type of atoms present in the formula.

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

If a chemical formula has a coefficient of 2 in front of H₂O, how many Hydrogen and Oxygen atoms are there?

• 2 Hydrogen atoms and 1 Oxygen atom

• 4 Hydrogen atoms and 1 Oxygen atom

• 4 Hydrogen atoms and 2 Oxygen atoms

• 2 Hydrogen atoms and 2 Oxygen atoms

Tags

NGSS.MS-PS1-1

In the formula 5C₂H₆, how many total Carbon and Hydrogen atoms are there?

• 10 Carbon atoms and 30 Hydrogen atoms.

• 5 Carbon atoms and 12 Hydrogen atoms.

• 8 Carbon atoms and 24 Hydrogen atoms.

• 6 Carbon atoms and 18 Hydrogen atoms.

Tags

NGSS.MS-PS1-1