Which compound is made up of three elements?
A. H2O2
B. CaCl2
C. HNO3
D. Na2O
Do you know how to count the elements in a chemical formula?
H O
Ca Cl
H N O
Na O
HNO3
To determine which compound is made up of three elements, we need to break down the chemical formulas and count the elements in each compound.
A. H2O2: This compound consists of hydrogen and oxygen. It has two hydrogen atoms and two oxygen atoms. So, it has two elements (hydrogen and oxygen).
B. CaCl2: This compound consists of calcium and chlorine. It has one calcium atom and two chlorine atoms. So, it also has two elements (calcium and chlorine).
C. HNO3: This compound consists of hydrogen, nitrogen, and oxygen. It has one hydrogen atom, one nitrogen atom, and three oxygen atoms. So, it has three elements (hydrogen, nitrogen, and oxygen).
D. Na2O: This compound consists of sodium and oxygen. It has two sodium atoms and one oxygen atom. So, it has two elements (sodium and oxygen).
Among the given compounds, only compound C (HNO3) is made up of three elements. Therefore, the correct answer is C.