Answer:
23 atoms
Step-by-step explanation:
Krypton (Kr) exists naturally as a mixture of six isotopes with atomic number of 36. These six isotopes occupy different percentages of the mixture. Below is a list of the isotopes and there percentage in a given mixture
1) Krypton-78 (⁷⁸Kr) ⇒ 0.35%
2) Krypton-80 (⁸⁰Kr) ⇒ 2.25%
3) Krypton-82 (⁸²Kr) ⇒ 11.6%
4) Krypton-83 (⁸³Kr) ⇒ 11.5%
5) Krypton-84 (⁸⁴Kr) ⇒ 57%
6) Krypton-86 (⁸⁶Kr) ⇒ 17.3%
To determine the amount of ⁸³Kr present in a mixture of 200 atoms of krypton, you will multiply the it's percentage of occurrence in nature by the amount of atoms in a given mixture
11.5/100 × 200 = 23 atoms
Hence, there should be 23 atoms of krypton-83 in the mixture of 200 atoms of Krypton.