Select all the correct answers.

Which two molecules are compounds?

A. [tex] NaHCO _3 [/tex]
B. [tex] O _3 [/tex]
C. [tex] Cl _2 [/tex]
D. [tex] C _8 H _{18} [/tex]



Answer :

To determine which molecules are compounds, we need to identify those that consist of more than one type of atom. A compound is defined as a substance formed when two or more different types of atoms bond together chemically.

Let’s examine each molecule:

1. NaHCO[tex]\(_3\)[/tex] (Sodium bicarbonate):
- This molecule contains four different types of atoms: sodium (Na), hydrogen (H), carbon (C), and oxygen (O).
- Since it consists of multiple types of atoms, [tex]\( NaHCO _3 \)[/tex] is a compound.

2. O[tex]\(_3\)[/tex] (Ozone):
- This molecule consists solely of oxygen (O) atoms.
- Since it consists of only one type of atom, [tex]\( O _3 \)[/tex] is not a compound.

3. Cl[tex]\(_2\)[/tex] (Chlorine gas):
- This molecule consists solely of chlorine (Cl) atoms.
- Since it consists of only one type of atom, [tex]\( Cl _2 \)[/tex] is not a compound.

4. C[tex]\(_8\)[/tex]H[tex]\(_{18}\)[/tex] (Octane):
- This molecule contains two different types of atoms: carbon (C) and hydrogen (H).
- Since it consists of multiple types of atoms, [tex]\( C _8 H _{18} \)[/tex] is a compound.

Therefore, the two molecules that are compounds are:

- [tex]\( NaHCO _3 \)[/tex]
- [tex]\( C _8 H _{18} \)[/tex]