among the elements of the main group, the first ionization energy increases\nfrom left to right across a…

among the elements of the main group, the first ionization energy increases\nfrom left to right across a period.\nfrom right to left across a period.\nwhen the atomic radius increases.\ndown a group.

among the elements of the main group, the first ionization energy increases\nfrom left to right across a period.\nfrom right to left across a period.\nwhen the atomic radius increases.\ndown a group.

Answer

Answer:

A. from left to right across a period.

Brief Explanation:

As you move from left to right across a period in the main - group elements, the effective nuclear charge increases while the shielding effect remains relatively constant. This makes it harder to remove an electron, thus increasing the first ionization energy.