Question

In general, how is the radius of an atom

related to the atom's attraction for outer-
level electrons?

Answer 1

The radius of an atom decreases from left to right across a period due to an increased effective nuclear charge, and increases from top to bottom within a group due to additional principal energy levels.

Step-by-step explanation:

In general, the radius of an atom is related to the atom's attraction for outer-level electrons through the concept of effective nuclear charge (Zeff). As you move from left to right across a period, the atomic radius tends to decrease despite the addition of electrons. This is because along with electrons, protons are added to the nucleus, and because the additional protons pull the electrons closer, the effective nuclear charge increases. Electrons added to the same principal energy level do not fully compensate for the increased pull from the nucleus. Thus, with a stronger effective nuclear charge, the electrons are held more tightly, resulting in a smaller atomic radius.

When considering the group trend in the periodic table, the atomic radius generally increases from top to bottom within a group. This increase is due to a higher number of occupied principal energy levels in atoms further down a group, with these higher energy levels containing orbitals that are larger. Although there is also an increase in positive nuclear charge, the effect of additional principal energy levels is dominant, leading to an increase in atomic radius.

Answer 2

Step-by-step explanation:

Atomic radius

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and nuclear attraction for outer electrons increases.

Atomic radii trend along group:

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.