Question

1. which element in each pair has the larger ionization energy? circle the correct answer.

a) na or o b) be or b c) ne or f d) cu or zn
e) i or ne f) k or v g) ca or fr h) w or se

Explanation:

Step1: Ionization energy trends

Ionization energy generally increases across a period (left - to - right) and decreases down a group. Noble gases have very high ionization energies due to their stable electron configurations.

• For a) Na (Group 1) and O (Group 16). O is to the right of Na in the periodic table.
• For b) Be (1s²2s²) has a filled s - subshell. B (1s²2s²2p¹). Removing an electron from Be requires more energy as it disrupts a filled subshell.
• For c) Ne (noble gas) has a stable electron configuration. F is one electron short of a noble gas configuration.
• For d) Zn has a completely filled 3d¹⁰4s² configuration. Removing an electron from Zn is more difficult than from Cu (3d¹⁰4s¹).
• For e) Ne (noble gas) has a higher ionization energy than I (halogen in a lower period).
• For f) V is to the right of K in the periodic table.
• For g) Ca is above Fr in the periodic table (ionization energy decreases down a group).
• For h) W is in a lower period but Se is a non - metal. However, considering the overall trend, Se has a higher ionization energy as W is a metal in a lower period.

Answer:

a) O, b) Be, c) Ne, d) Zn, e) Ne, f) V, g) Ca, h) Se