What is the mass number of an atom that consists of 20 protons, 20 neutrons, and 18 electrons?
Answer:
Mass no. = protons + neutrons = 20 + 20 = 40
Hence the element is Calcium
But since there are 2 fewer electrons (proton and electron number in an elemental atom should be equal) it is an ion.
So the ion is Ca2+
Use the farmula....
Mass number = no of proton + no of neutron.
In an atom no of electron is equal to no of proton.(here 2 electron may be lost by the atom)
Mass no = 20 + 20 = 40
It is a Ca^+2 ion.
Atomic mass = 40 = Calcium with 18 electrons is a calcium ion Ca ++.
The answers post by the user, for information only, FunQA.com does not guarantee the right.
More Questions and Answers: