To determine the mass of \( \text{CO}_2 \) (carbon dioxide) in atomic mass units (amu), let's break it down step by step:
1. Identify the atoms in \( \text{CO}_2 \):
- \( \text{CO}_2 \) consists of 1 carbon (C) atom and 2 oxygen (O) atoms.
2. Find the atomic masses:
- The atomic mass of carbon (C) is 12 amu.
- The atomic mass of oxygen (O) is 16 amu.
3. Calculate the total atomic mass of \( \text{CO}_2 \):
- The molecule has 1 carbon atom and 2 oxygen atoms.
- Therefore, the total atomic mass is given by the sum of the atomic masses of all the atoms in the molecule.
4. Sum the atomic masses:
- The atomic mass of the carbon atom is \( 12 \) amu.
- The combined atomic mass of the two oxygen atoms is \( 2 \times 16 \) amu, which equals \( 32 \) amu.
- Adding these together:
[tex]\[
12 \text{ amu} + 32 \text{ amu} = 44 \text{ amu}
\][/tex]
Therefore, the mass of \( \text{CO}_2 \) in atomic mass units is \( 44 \) amu.
The correct answer is:
A. [tex]\( 44 \text{ amu} \)[/tex]