Which statement correctly compares the atomic mass and atomic number of helium?

• A. The atomic mass and atomic number of helium are equal.
• B. The atomic mass of helium is less than its atomic number.
• C. The atomic mass of helium is approximately twice its atomic number.
• D. The atomic mass of helium is approximately half its atomic number.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the definitions of atomic number and atomic mass. The atomic number (Z) is the number of protons in the nucleus of an atom, which defines the element. The atomic mass (A) is the total number of protons and neutrons in the nucleus.
2. Step 2: Identify the atomic number of helium. Helium has 2 protons, so its atomic number is 2.
3. Step 3: Determine the atomic mass of helium. Helium typically has 2 neutrons in addition to its 2 protons, so its atomic mass is approximately 4 (2 protons + 2 neutrons).
4. Step 4: Compare the atomic mass and atomic number of helium. Since the atomic mass (about 4) is roughly twice the atomic number (2), the atomic mass is approximately twice the atomic number.
5. Step 5: Conclude that the correct statement is: 'The atomic mass of helium is approximately twice its atomic number.'