Identify the elements X and Y using the IE values given below:

| | (kJ/mol) | (kJ/mol) |
|---|---|---|
| X | 495 | 4563 |
| Y | 731 | 1450 |

Question

Identify the elements X and Y using the IE values given below:

| |  (kJ/mol) |  (kJ/mol) |
|---|---|---|
| X | 495 | 4563 |
| Y | 731 | 1450 |

Canvas Classes · Accepted Answer

Strategy:
 Identify groups based on the jump in successive ionization energies. A massive jump between  and  indicates a Group 1 alkali metal. A moderate increase indicates Group 2.

Step 1: Evaluate Element X
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The jump is 9-fold. The second electron is removed from a stable noble gas core (). Thus, X is Sodium ().

Step 2: Evaluate Element Y
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The increase is roughly 2-fold. Both electrons are in the valence shell. Thus, Y is Magnesium ().

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