Counting Atoms Practice

Front

What is the definition of an element in chemistry?

Back

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

Front

How do you determine the number of elements in a chemical formula?

Back

Count the different capital letters in the formula, as each capital letter represents a different element.

Front

In the compound CaCO₃, how many elements are present?

Back

There are 3 elements: Calcium (Ca), Carbon (C), and Oxygen (O).

Front

What does the subscript in a chemical formula indicate?

Back

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

Front

How many hydrogen atoms are in the compound C₈H₁₀N₄O₂?

Back

There are 10 hydrogen atoms.

Front

What is the formula for baking soda?

Back

The formula for baking soda is NaHCO₃.

Front

How many molecules are represented by the formula 3 NaHCO₃?

Back

There are 3 molecules of NaHCO₃.

Front

In the compound NaHCO₃, how many different elements are present?

Back

There are 4 different elements: Sodium (Na), Hydrogen (H), Carbon (C), and Oxygen (O).

Front

What is the chemical formula for table salt?

Back

The chemical formula for table salt is NaCl.

Front

How many atoms of chlorine are in the compound 4 NaCl?

Back

There are 4 atoms of chlorine.