Neutrons from mass number minus protons

Steps:

• Atomic number of boron is 5, matching the number of protons.
• Mass number is 11, the sum of protons and neutrons.
• Neutrons = mass number - protons.
• 11 - 5 = 6 neutrons.

Why C is correct:

• Mass number A = protons Z + neutrons N, so N = A - Z = 11 - 5 = 6.

Why the others are wrong:

• A. 1: Subtracts protons from twice the atomic number, ignoring mass number.
• B. 5: Equals protons, confusing atomic number with neutrons.
• D. 11: Equals mass number, including protons as neutrons.

Final answer: C