3. Write the following isotope in hyphenated form (e. g., "carbon-14”): Kr a. Krypton-109
b. Krypton -37
c. Krypton -36
d. Krypton -73

D. Krypton-73

Explanation:

An isotope of an element has the same atomic number and the same number of protons but a different number of neutrons and a different atomic weight. Krypton is the 36th element on the periodic table. It has 36 protons and 48 neutrons. Krypton-73 is one of 33 known isotopes of Krypton and is the only one that actually exists from the list of choices.

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