This is how krypton appears in the periodic table. a purple box has k r at the center and 36 above. below it says krypton and below that 83.80.

rounded to the nearest whole number, how many protons are in an atom of krypton?

36
48
84
120

The number of protons in an atom of krypton is 36.

Explanation:

The number written above the symbol of Kr in the periodic table represents the atomic number of the element . Then the number written in the below represents the mass number.

So the mass number of krypton is 84 and the atomic number of krypton is 36. As it is known that number of protons and electrons will be equal in a stable element. Thus, the krypton atom will be having 36 protons.