Francium (Fr) has the lowest ionization energy in Group 1 because - it has the greatest number of protons, so it attracts its electrons the strongest

it has the smallest number of valence electrons in its outermost shell

its 1 valence electron is very far from the nucleus, so little energy is needed to remove it

it has the greatest atomic mass

The ionization energy or potential measures the amount of energy required to remove an isolated electron from an atom (valence electron). Hence, Francium has the lowest ionization energy because its 1 valence electron is very far from the nucleus, so little energy is needed to remove it.

Therefore, Francium has the lowest ionization energy because its 1 valence electron is very far from the nucleus, so little energy is needed to remove it

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Francium (Fr) has the lowest ionization energy in Group 1 because -its 1 valence electron is very far from the nucleus, so little energy is needed to remove it

Ionization energy is the energy that an atom needs in the gas phase to release its electrons

the atomic number of the elements in group 1A:

The atomic number indicates the number of electrons and protons.

atomic number = number of electrons = number of protons

As the number of electrons increases from top to bottom, the number of shells will increase(the radius of the atom tends to get bigger) so that the tendency to remove the outer electrons is easier and the ionization energy is also smaller(the attraction of the atomic nucleus to the outer electrons  (valence electron) weaker)

Ionization energy is the attraction of the nucleus to electrons, not protons

The valence electrons in group 1 are the same which is 1

The mass number is not related to the ionization energy

c

explanation: