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 each type of atom in the chemical formula [tex]\(Ca(OH)_2\)[/tex], let's break down the formula step by step.

1. Identify the elements and their counts inside the formula:

- [tex]\(Ca\)[/tex] stands for calcium.
- [tex]\((OH)_2\)[/tex] indicates a hydroxide group, and the subscript 2 indicates that there are two of these groups.

2. Determine the number of calcium atoms:
- There is no subscript next to [tex]\(Ca\)[/tex], which means there is 1 calcium atom.

3. Determine the number of each type of atom in the hydroxide group [tex]\((OH)_2\)[/tex]:

- The hydroxide group [tex]\(OH\)[/tex] consists of one oxygen (O) and one hydrogen (H).
- The subscript "2" outside the parentheses means that everything inside the parentheses is multiplied by 2.

Therefore:
- Number of oxygen atoms: [tex]\(2 \times 1 = 2\)[/tex]
- Number of hydrogen atoms: [tex]\(2 \times 1 = 2\)[/tex]

4. Summarize the total number of each kind of atom:

- Calcium ([tex]\(Ca\)[/tex]): 1 atom
- Oxygen ([tex]\(O\)[/tex]): 2 atoms
- Hydrogen ([tex]\(H\)[/tex]): 2 atoms

So, the chemical formula [tex]\(Ca(OH)_2\)[/tex] consists of:
- 1 calcium atom,
- 2 oxygen atoms,
- 2 hydrogen atoms.

Hence, the correct answer is:

1 calcium, 2 oxygen, and 2 hydrogen