Answer
See explanation
Work Step by Step
a) Trend: Atomic radius decreases across a period (left to right) and increases down a group.
[1] is in Group 17, Period 2
[2] is in Group 2, Period 3
[1] has the smaller atomic radius because it's farther to the right and higher up on the periodic table.
b) Trend: Ionization energy increases across a period and up a group.
[1] is a nonmetal with a high tendency to gain electrons, so it holds onto its electrons tightly.
[2] is a metal and more willing to lose electrons.
Answer: [2] has the lower ionization energy.
(c) Identify the elements
[1} is Fluorine (F): Atomic number 9, a halogen, highly electronegative.
[2] is Magnesium (Mg): Atomic number 12, an alkaline earth metal, reactive with acids and water.
