Counting Atoms

Front

What is a chemical formula?

Back

A chemical formula is a way of expressing the number and type of atoms in a molecule using symbols and subscripts.

Front

What does a subscript in a chemical formula indicate?

Back

A subscript indicates the number of atoms of the element that are present in the molecule.

Front

How many atoms are in the molecule H₂O?

Back

There are 3 atoms in H₂O (2 Hydrogen and 1 Oxygen).

Front

What is the total number of atoms in the formula C₆H₁₂O₆?

Back

There are 24 atoms in C₆H₁₂O₆ (6 Carbon, 12 Hydrogen, and 6 Oxygen).

Front

What is the significance of the coefficient in a chemical formula?

Back

A coefficient indicates how many molecules of the compound are present.

Front

How many elements are in the compound NaCl?

Back

There are 2 elements in NaCl (Sodium and Chlorine).

Front

What is the formula for calculating the total number of atoms in a compound?

Back

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

Front

What is the chemical formula for 1 atom of nickel and 2 atoms of fluorine?

Back

The chemical formula is NiF₂.

Front

How many hydrogen atoms are in 3(NH₄)₂CrO₄?

Back

There are 24 hydrogen atoms in 3(NH₄)₂CrO₄.

Front

What does the term 'element' refer to in chemistry?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means.