How many atoms are present in a molecule of hydrogen (H_2)?

• A. 2
• B. 3
• C. 4
• D. 1

Answer: (A)

Verified step by step guidance

1. Identify the molecular formula of hydrogen gas, which is given as H_2. This means each molecule consists of hydrogen atoms bonded together.
2. Understand that the subscript '2' in H_2 indicates the number of hydrogen atoms in one molecule of hydrogen gas.
3. Recall that the subscript in a chemical formula tells you how many atoms of that element are present in one molecule.
4. Since the formula is H_2, it means there are 2 hydrogen atoms in one molecule of hydrogen gas.
5. Therefore, the number of atoms present in a molecule of hydrogen (H_2) is 2.