Question

<. Identify the element.
9. Calculate the nu
Ans. It has 15 electra
10. The atomic number of
these elements is 40. What i
the number of electrons, protons and neutrons in
5 electrons, 15 protons and 16 neutrons. The element is phosphorus.
umber of calcium is 20 and 18 respectively, but the mass number of both
is 40. What is the name given to such a pair of elements? Do they have same
nber of electrons, protons and neutrons?
icobars. They do not have same number of alnatronna
NU​

Answer 1

Answer:

protons in its atomic nuclei. In a neutral atom, the number of electrons are the same as the number of protons. The atomic mass (mass number) is the sum of the protons and neutrons in the nucleus. Mass number can vary due to the fact that the number of neutrons can vary. Isotopes are named for their mass numbers.

So, this element has 15 protons (atomic number), 15 electrons, and 16 neutrons (mass number minus atomic number).

This isotope is phosphorus-31, which has atomic number 15.