Ionic Radius

Which ion has the smaller radius?

• P^-3

• Cl^-1

• S^-2

• all are anions in the same period so they are the same size

Which is the smaller atom: Mg or Mg⁺²?

• Mg because it gains an energy level since it gains 2 electrons.

• Mg due to extra electron repulsion created by gaining 2 electrons.

• Mg⁺² because of extra electron repulsion created by gaining 2 electrons.

• Mg⁺² because it loses an energy level since it loses 2 electrons.

When an atom gains an electron, the size of atom

• will increase

• will decrease

• will not change

Answer explanation

When an atom gains an electron, the size of the atom will increase due to the increased electron-electron repulsion, causing the electron cloud to expand.

When an atom loses an electron the size of atom

• will increase

• will decrease

• will not change

Answer explanation

When an atom loses an electron, the size of the atom will decrease. This is because the electron is negatively charged and its removal reduces the electron-electron repulsion, causing the remaining electrons to be pulled closer to the nucleus, resulting in a smaller size.

Which of the following statements are true?

• For metallic elements, the ionic radius > the atomic radius

• For metallic elements, the ionic radius < the atomic radius

• For nonmetallic elements, the atomic radius > ionic radius

• For nonmetallic elements, the atomic radius < ionic radius

Answer explanation

For metallic elements, the ionic radius < the atomic radius

Anions have ionic radii that are larger than their atomic radii.

• True

• False

Answer explanation

Anions have gained electrons, leading to increased electron-electron repulsion and larger ionic radii compared to their atomic radii.

The different size between Cl and Cl- is because

• They have different effective nuclear charge

• They have different number of shells

• Cl- has stronger electron repulsion

• Cl has stronger electron repulsion

Answer explanation

Cl- has stronger electron repulsion

Nucleus attraction towards valence electron in Cl is ________ compared to in Cl^-. So that the size of Cl is ______ compared to Cl^-.

• stronger, smaller

• weaker, bigger

• stronger, bigger

• weaker, smaller

Answer explanation

Nucleus attraction towards valence electron in Cl is stronger compared to in Cl-. This results in the size of Cl being smaller compared to Cl-.

Tags

NGSS.HS-PS1-3

Which ion has the largest ionic radius?

• A) Na^+

• B) Mg^2+

• C) Al^3+

• D) Cl^-

What happens to the ionic radius when an atom loses an electron to form a cation?

• A) It increases

• B) It decreases

• C) It remains the same

• D) It becomes zero