The energy absorbed or released when a neutral atom loses one electron

ionization energy

Explanation:

Ionization energy is the energy required to remove the most loosely bound electron from a gaseous atom.

Metals have low ionization energy as they tend to attain stable configuration by losing the valence electrons. Example: Sodium

Nobles gases have high ionization energy as they do not tend to lose electrons easily due to their high stability.

In a group, the ionization energy decreases as we move down as the size increases and thus the valence shell moves farther from nucleus and thus is easier to remove.

In a period, the ionization energy increases as we move across, the size decreases and thus the valence shell moves near to the nucleus and thus it gets difficult to remove.

iron and sleel

make siroeel

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.