To determine which molecule contains the fewest number of atoms, we will analyze each molecule's atomic composition and count the number of atoms in each.
1. SmCl₃:
- This molecule consists of one Samarium (Sm) atom and three Chlorine (Cl) atoms.
- Therefore, the total number of atoms in SmCl₃ is:
[tex]\[
1 (\text{Sm}) + 3 (\text{Cl}) = 4 \text{ atoms}
\][/tex]
2. RbNO₃:
- This molecule consists of one Rubidium (Rb) atom, one Nitrogen (N) atom, and three Oxygen (O) atoms.
- Therefore, the total number of atoms in RbNO₃ is:
[tex]\[
1 (\text{Rb}) + 1 (\text{N}) + 3 (\text{O}) = 5 \text{ atoms}
\][/tex]
3. H₂SeO₃:
- This molecule consists of two Hydrogen (H) atoms, one Selenium (Se) atom, and three Oxygen (O) atoms.
- Therefore, the total number of atoms in H₂SeO₃ is:
[tex]\[
2 (\text{H}) + 1 (\text{Se}) + 3 (\text{O}) = 6 \text{ atoms}
\][/tex]
4. SiH₄:
- This molecule consists of one Silicon (Si) atom and four Hydrogen (H) atoms.
- Therefore, the total number of atoms in SiH₄ is:
[tex]\[
1 (\text{Si}) + 4 (\text{H}) = 5 \text{ atoms}
\][/tex]
Now we will compare the total number of atoms in each molecule:
- SmCl₃: 4 atoms
- RbNO₃: 5 atoms
- H₂SeO₃: 6 atoms
- SiH₄: 5 atoms
Among these, the molecule with the fewest number of atoms is SmCl₃ with 4 atoms.
Therefore, the molecule that contains the fewest number of atoms is SmCl₃.
