Which of the following is the composition of an isotope of calcium (atomic number 20)?
22 protons, 20 neutrons, 19 electrons
19 protons, 20 neutrons, 19 electrons
20 protons, 25 neutrons, 20 electrons
21 protons, 20 neutrons, 20 electrons
sorry i asked this question like 2 times. i just really need the answer!! i thought calcium had 20 protons and 20 neutrons but there is no option like that :( so confused, please help!
- 7 years ago
A calcium Atom needs to have 20 atoms. It's atomic number gives that away. the number of neutrons can vary. That's where the word "isotope" comes in. An atom can have many isotopes with the same number of PROtons but a different number of NEUtrons