Question

Which of the following statements about ionization energy is true?
A. Potassium has a lower ionization energy than sodium.
B. Ionization energy is the amount of energy used to add an electron to an atom.
C. In a period, elements farther to the right generally have lower ionization energies than elements on the left.
D. Elements toward the bottom of a group periodic table generally have higher ionization energies than elements at the top of the group.

Answer 1

Ionization energy is the amount of energy needed to expel an electron from an atom so its not B

Hint :- potassium as more inner shielding electrons than sodium.

Answer 2

A. Potassium has a lower ionization energy than sodium.
Ionization energy is the energy required to make an atom lose an electron. (Provide enough mean kinetic energy that the outermost electron can escape the attraction.) Since Potassium has more number of shells than sodium, the distance between the electron and the nucleus is greater in potassium than sodium. We also know that attractive force are inversely proportional to square of distance so if distance increases, the attraction decreases.
Moreover, the inner electrons also repel the outer electron. The repulsion is greater in potassium due to more number of inner electrons
You can argue that the attraction is much greater in potassium than sodium due to increased nuclear charge. True but those two factors are much dominant in front of increment of nuclear charge

Answer 3

SO ITS A?

Answer 4

What do you think? Do you have a reason to justify the other options? If so, please share with us

Answer 5

Basically all this information means that the out electron in the potassium atom is not as 'strongly held' as the one in the sodium atom.

Answer 6

- so it is more easily lost