The atomic number of calcium is 20 which means it has 20 protons and as an atom (not an ion) it also has 20 electrons. These are in four energy levels (1 though 4) .
Answer:
28
Explanation:
electron = atomic number - charge(if the charge is positive and addition if the charge is negative)
electron = 30 - 2
electron = 28
The question is incomplete, the complete question is;
The lightest particle among the following is:
• Electron •Proton • Neutron • Alpha
Answer:
Electron
Explanation:
There three basic subatomic particles are electrons, protons and neutrons. Both protons and neutrons are found in the nuclear and both contribute towards the mass of the atom. The alpha particle has the same mass as the helium nucleus.
However, the electrons are found in orbiit and have a negligible mass compared to the mass of the protons and neutrons. The mass of the electron is about 9.11 × 10^-31 Kg. This makes it the lightest of all the particles listed among the options.
