An atom of ⁸²Kr contains ________ neutrons. A) 36 B) 118 C) 46 D) 80 E) 82

Question

Quizplus · Accepted Answer

The numbers in the symbol represent the number of atoms of each element in the molecule:
- S1U1 (unknown element, possibly a typo) 
- P182 
- S1 
- S1 
- P0 
- Kr (krypton)

Since 1U1 is unknown and not on the periodic table, we can ignore it. 
The sum of the atomic numbers of the remaining elements gives us the total number of protons in the atom: 
(15 + 182 + 16 + 16 + 15 + 36) = 280

The atomic number represents the number of protons and neutrons, therefore the number of neutrons can be calculated by subtracting the atomic number (280) by the number of protons (sum of atomic numbers of the elements without Kr, which is 264 in this case): 
280 - 264 = 16

Therefore, the atom contains 16 neutrons.

An Atom of 82Kr Contains ________ Neutrons

An Atom of ⁸²Kr Contains ________ Neutrons