How many protons and neutrons are present in the isotope Cl-37?

• A. 17 protons and 20 neutrons
• B. 18 protons and 19 neutrons
• C. 17 protons and 37 neutrons
• D. 20 protons and 17 neutrons

Answer: (A)

Verified step by step guidance

1. Identify the element from the isotope notation. In this case, Cl-37 refers to chlorine with a mass number of 37.
2. Recall that the atomic number of chlorine (Cl) is 17, which means chlorine has 17 protons. The atomic number is the number of protons in the nucleus and is unique to each element.
3. Use the mass number (given as 37) to find the total number of protons and neutrons combined in the nucleus. The mass number is the sum of protons and neutrons.
4. Calculate the number of neutrons by subtracting the number of protons from the mass number using the formula: \(\text{Number of neutrons} = \text{Mass number} - \text{Number of protons}\).
5. Substitute the values: \(\text{Number of neutrons} = 37 - 17\). This will give you the number of neutrons in the isotope Cl-37.