How many neutrons does calium have?

Answer 1

It depends on which isotope of Calcium you are talking about. The most abundant isotope is ⁴⁰Ca, and the atomic number (number of protons) for Ca is 20, so the difference between the rounded isotopic weight given as a superscript on the left side of the elemental symbol and atomic number is, 40-20=20 neutrons. But really knowing about this...the atomic weight for Ca is 40.081 g/mol, and it is found by the summing the weighted contribution of the naturally occurring isotopes, i.e., the atomic weight on the periodic table is the fractional atomic weight of all the isotopes for that element.

For Ca,

39.962589*.9697+41.958625*.0064+42.958780*.0015+43.955491*.0206+47.952531*.0019=40.08129 g/mol

which gives using the notation,

⁴⁰Ca, ⁴²Ca, ⁴³Ca, ⁴⁴Ca, ⁴⁸Ca

So, ⁴⁰Ca=20 neutrons, ⁴²Ca=22 neutrons, ⁴³Ca=23 neutrons, ⁴⁴Ca=24 neutrons, ⁴⁸Ca=28 neutrons.

Answer 2

Do you mean Calcium??

If so, then Calcium has atomic # = 20 and mass # = 40.

Mass # = # of protons + # of neutrons

Atomic # tells you the # of protons, which = 20.

40 = 20 + # of neutrons

# of neutrons = 40 - 20 = 20