Counting Atoms

Front

What is a compound?

Back

A compound is a substance formed when two or more different elements are chemically bonded together. Example: CO2 (carbon dioxide) is a compound.

Front

How many atoms of Oxygen are in Fe(NO3)3?

Back

There are 9 atoms of Oxygen in Fe(NO3)3.

Front

What does it mean if there is no subscript following an element symbol?

Back

It means there is only 1 atom of that element.

Front

What is C2H8O?

Back

C2H8O is a compound.

Front

How many Hydrogen atoms are in 4H2O?

Back

There are 8 Hydrogen atoms in 4H2O.

Front

What is the chemical formula for water?

Back

The chemical formula for water is H2O.

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.

Front

What does a subscript in a chemical formula indicate?

Back

A subscript indicates the number of atoms of the element in the compound. For example, in H2O, the '2' indicates there are 2 Hydrogen atoms.

Front

What is the total number of atoms in CO2?

Back

There are 3 atoms in CO2 (1 Carbon atom and 2 Oxygen atoms).

Front

How do you determine the number of atoms in a compound?

Back

Count the number of atoms for each element in the chemical formula, including subscripts.