Compared to the stable reference element, an isotope is different in what way?
question 1 options:
a) more protons in the nucleus
b) fever electrons in the orbitals
c) more electrons in the orbitals
d) fewer neutrons in the nucleus
e) more neutrons in the nucleus

E) More neutrons in the nucleus

Explanation:

Isotope -

The atoms which have same number of protons but different number of neutrons.

And since , atomic number = protons number

and , mass number = proton + neutrons .

Hence ,

The atomic number will not change , but the mass number will change .

Hence , the correct option is more neutrons in the nucleus .

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.