Counting Atoms

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means. Each element is made up of atoms that have the same number of protons.

Front

How do you count atoms in a chemical formula?

Back

To count atoms in a chemical formula, identify each element and its subscript. The subscript indicates the number of atoms of that element. If there is no subscript, it means there is one atom of that element.

Front

What does the subscript in a chemical formula represent?

Back

The subscript in a chemical formula represents the number of atoms of the element that precedes it.

Front

How many elements are in the compound Mg₂As₃COHNi₂?

Back

There are 6 elements: Magnesium (Mg), Arsenic (As), Carbon (C), Oxygen (O), Hydrogen (H), and Nickel (Ni).

Front

In the compound (NH₄)₂CrO₄, how many Nitrogen atoms are present?

Back

There are 2 Nitrogen atoms.

Front

What is a compound?

Back

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

Front

How many Sodium atoms are in 6NaCl?

Back

There are 6 Sodium atoms.

Front

What is the total number of atoms in the compound H₂O?

Back

There are 3 atoms in total: 2 Hydrogen atoms and 1 Oxygen atom.

Front

How many atoms of Hydrogen are in the compound H₂SO₄?

Back

There are 2 Hydrogen atoms.

Front

What is the periodic table?

Back

The periodic table is a tabular arrangement of chemical elements, organized by their atomic number, electron configuration, and recurring chemical properties.