Counting Atoms Flashcard

Front

What is a subscript in a chemical formula?

Back

A subscript is a small number written below the element symbol that indicates the number of atoms of that element in a molecule.

Front

What does a coefficient represent in a chemical equation?

Back

A coefficient is a number placed in front of a chemical formula that indicates how many molecules or moles of that substance are present.

Front

How do you calculate the total number of atoms in a chemical formula?

Back

To calculate the total number of atoms, sum the products of the subscripts and coefficients for each element in the formula.

Front

In the formula H₂SO₄, how many total atoms are present?

Back

There are 7 total atoms: 2 Hydrogen, 1 Sulfur, and 4 Oxygen.

Front

How many Hydrogen atoms are in the compound 3(NH₄)₂CrO₄?

Back

There are 24 Hydrogen atoms.

Front

What is the significance of parentheses in chemical formulas?

Back

Parentheses indicate that the enclosed elements and their subscripts should be multiplied by the coefficient outside the parentheses.

Front

How many Nitrogen atoms are in the compound (NH₄)₂CrO₄?

Back

There are 2 Nitrogen atoms.

Front

What is the difference between a subscript and a coefficient?

Back

A subscript indicates the number of atoms of an element in a molecule, while a coefficient indicates the number of molecules of a compound.

Front

What is the formula for calculating the number of Oxygen atoms in 2H₂O?

Back

The number of Oxygen atoms is calculated as 2 (coefficient) x 1 (subscript) = 2 Oxygen atoms.

Front

How do you determine the number of atoms of an element in a compound with multiple elements?

Back

Count the number of atoms for each element by multiplying the subscript by the coefficient, then sum them for the total.