How many atoms of each element are in the chemical formula [tex]$Ca(OH)_2$[/tex]?

A. 1 calcium, 1 oxygen, and 1 hydrogen
B. 1 calcium, 2 oxygen, and 2 hydrogen
C. 2 calcium, 1 oxygen, and 2 hydrogen
D. 2 calcium, 2 oxygen, and 2 hydrogen



Answer :

To determine the number of atoms of each element in the chemical formula [tex]\( \text{Ca(OH)}_2 \)[/tex], we need to break down the formula into its constituent elements. Let's do this step-by-step:

1. Identify the elements in the formula:
The chemical formula [tex]\( \text{Ca(OH)}_2 \)[/tex] consists of calcium (Ca), oxygen (O), and hydrogen (H).

2. Count the calcium atoms:
There is no subscript after Ca, which means there is only 1 calcium atom.

3. Analyze the [tex]\((\text{OH})_2\)[/tex] group:
- The notation [tex]\((\text{OH})_2\)[/tex] indicates that there are 2 hydroxide (OH) groups. Each hydroxide group contains:
- 1 oxygen atom (O)
- 1 hydrogen atom (H)

4. Calculate the total number of atoms for oxygen and hydrogen:
- Since there are 2 hydroxide groups, we multiply the number of oxygen and hydrogen atoms by 2.
- Oxygen: [tex]\(2 \times 1 = 2\)[/tex]
- Hydrogen: [tex]\(2 \times 1 = 2\)[/tex]

Summarizing the counts, we have:
- 1 calcium atom (Ca)
- 2 oxygen atoms (O)
- 2 hydrogen atoms (H)

The correct answer is:
[tex]\[ \text{1 calcium, 2 oxygen, and 2 hydrogen} \][/tex]