To determine the number of neutrons in an atom, you need to subtract the atomic number from the mass number. The atomic number represents the number of protons, while the mass number is the total number of protons and neutrons in the atom's nucleus.
Given:
- The atomic number of krypton (Kr) is 36.
- The mass number of krypton (Kr) is 84.
The formula to find the number of neutrons is:
[tex]\[ \text{Number of neutrons} = \text{Mass number} - \text{Atomic number} \][/tex]
Let's perform the calculation:
[tex]\[ \text{Number of neutrons} = 84 - 36 = 48 \][/tex]
Thus, the number of neutrons in krypton (Kr) is 48.
The correct answer is:
C. 48