Counting Atoms

Front

What is an atom?

Back

An atom is the smallest unit of matter that retains the properties of an element. It consists of a nucleus made of protons and neutrons, surrounded by electrons.

Front

What is a molecule?

Back

A molecule is a group of two or more atoms bonded together, representing the smallest fundamental unit of a chemical compound.

Front

What does a coefficient in a chemical equation represent?

Back

A coefficient indicates the number of molecules or moles of a substance in a chemical reaction.

Front

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

Back

To count the total number of atoms, add the subscripts of each element in the formula, and multiply by the coefficient if present.

Front

What is a subscript in a chemical formula?

Back

A subscript is a number written below and to the right of an element symbol that indicates the number of atoms of that element in a molecule.

Front

In the formula H₂O, how many hydrogen atoms are there?

Back

There are 2 hydrogen atoms in the formula H₂O.

Front

In the formula C₆H₁₂O₆, how many total atoms are there?

Back

There are 24 total atoms in C₆H₁₂O₆ (6 Carbon + 12 Hydrogen + 6 Oxygen).

Front

What is the significance of the chemical formula NaCl?

Back

NaCl represents sodium chloride, which consists of one sodium atom and one chlorine atom, making a total of 2 atoms.

Front

How many atoms are in the compound 3H₂SO₄?

Back

There are 18 atoms in 3H₂SO₄ (3 x (2 H + 1 S + 4 O) = 3 x 7 = 21).

Front

What is the difference between an element and a compound?

Back

An element is a pure substance made of only one type of atom, while a compound is made of two or more different types of atoms chemically bonded together.