Question

Which statement correctly compares barium nitrate (Ba(NO3)2) and scandium nitrate (Sc(NO3)3)? (2 points)
Group of answer choices

They contain the same number of NO3 groups.

They contain the same number of oxygen atoms.

They contain the same total number of atoms.

They contain the same number of elements.

Answer 1

To compare barium nitrate (Ba(NO3)2) and scandium nitrate (Sc(NO3)3), let's break down the composition of each compound:

1. **Barium Nitrate (Ba(NO3)2)**:
- It contains 1 barium (Ba) atom.
- It contains 2 nitrate (NO3) groups, and each nitrate has 3 oxygen atoms.
- Therefore, it has 2 × 3 = 6 oxygen atoms and a total of 2 nitrate groups.
- Total atoms: 1 Ba + 2 × (1 N + 3 O) = 1 + 2(4) = 1 + 8 = 9 atoms in total.

2. **Scandium Nitrate (Sc(NO3)3)**:
- It contains 1 scandium (Sc) atom.
- It contains 3 nitrate (NO3) groups, and each nitrate has 3 oxygen atoms.
- Therefore, it has 3 × 3 = 9 oxygen atoms and a total of 3 nitrate groups.
- Total atoms: 1 Sc + 3 × (1 N + 3 O) = 1 + 3(4) = 1 + 12 = 13 atoms in total.

Now, let's analyze the statements:

- **They contain the same number of NO3 groups.**
Incorrect. Ba(NO3)2 has 2 NO3 groups, while Sc(NO3)3 has 3 NO3 groups.

- **They contain the same number of oxygen atoms.**
Incorrect. Ba(NO3)2 has 6 oxygen atoms, while Sc(NO3)3 has 9 oxygen atoms.

- **They contain the same total number of atoms.**
Incorrect. Ba(NO3)2 has 9 total atoms, while Sc(NO3)3 has 13 total atoms.

- **They contain the same number of elements.**
Correct. Both compounds contain 3 different elements: barium (Ba) or scandium (Sc), nitrogen (N), and oxygen (O) or 1 Sc, N, and O for Sc(NO3)3.

Therefore, the correct answer is:

**They contain the same number of elements.**