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. Molecules can be made of the same or different elements.

Front

What is a compound?

Back

A compound is a substance formed when two or more different elements are chemically bonded together in a fixed ratio.

Front

How many atoms are in a molecule of water (H2O)?

Back

A molecule of water contains 3 atoms: 2 hydrogen atoms and 1 oxygen atom.

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.

Front

What does the subscript in a chemical formula indicate?

Back

The subscript in a chemical formula indicates the number of atoms of the element present in the molecule. For example, in H2O, the '2' indicates there are 2 hydrogen atoms.

Front

Which element is least likely to form a compound?

Back

Noble gases, like Argon, are least likely to form compounds because they have a full outer shell of electrons.

Front

How many atoms of Carbon are in the formula C6H12O6?

Back

There are 6 atoms of Carbon in the formula C6H12O6.

Front

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

Back

To find the total number of atoms in a compound, add the number of atoms of each element present in the formula.

Front

What is the significance of the chemical formula MgSO4?

Back

The chemical formula MgSO4 indicates that the compound contains 1 Magnesium atom, 1 Sulfur atom, and 4 Oxygen atoms.