A=Mass number=24
N=neutrons=13
Z=atomic number.
A=Z+N
24=Z+13
Z=24-13
Z=11
The atomic number is 11, and this atom is sodium.
These masses are isotopes. By definition, isotopes of an element have the same number of protons as the given element, but different numbers of neutrons.
The metallic elements located anywhere between 3-12 of the periodic table
Explanation:
After the electron configuration, the last shell of the beryllium atom has two electrons. In this case, both the valence and valence electrons of beryllium are 2. We know the details about this. The elements that have 1, 2, or 3 electrons in the last shell donate the electrons in the last shell during bond formation.