Final answer:
The isotope calcium-40 has 20 protons, 20 electrons, and 20 neutrons, making option a) the correct answer.
Step-by-step explanation:
To determine the number of protons, electrons, and neutrons in the isotope calcium-40 (40Ca), we should look at the atomic number and the mass number. The atomic number of calcium is 20, which tells us that there are 20 protons; and since the atom is neutral, there are also 20 electrons. The mass number is 40, which is the sum of protons and neutrons. To find the number of neutrons, we subtract the number of protons (20) from the mass number (40).
Number of neutrons = 40 - 20 = 20
Therefore, the correct number of protons, electrons, and neutrons in calcium-40 is:
- Protons: 20
- Electrons: 20
- Neutrons: 20
Hence, the correct answer is a) Protons: 20, Electrons: 20, Neutrons: 20.