Which of the following statements about krypton (Kr) is correct?

• A. Krypton has an atomic number of 36.
• B. Krypton is located in period 3 of the periodic table.
• C. Krypton has 18 protons in its nucleus.
• D. Krypton has 36 neutrons in its most abundant isotope.

Answer: (A)

Verified step by step guidance

1. Recall that the atomic number of an element is the number of protons in its nucleus. This number uniquely identifies the element.
2. Look up krypton (Kr) on the periodic table to find its atomic number, which tells you how many protons it has.
3. Determine the period of krypton by locating its row on the periodic table. Periods are horizontal rows numbered from 1 to 7.
4. Understand that the number of neutrons in an isotope is calculated by subtracting the atomic number (number of protons) from the mass number (total protons + neutrons) of that isotope.
5. Identify the most abundant isotope of krypton and check its mass number to calculate the number of neutrons, then compare this to the given statements.