Question

question 10. four elements are shown in the diagram below. which element has the highest first ionization energy according to the position of the elements on the periodic table? diagram of periodic table with elements 1,2,3,4 marked possible points: 10 options: element 1, element 2, element 3, element 4

Explanation:

Step1: Recall ionization energy trend

First ionization energy (IE) generally increases across a period (left to right) and decreases down a group (top to bottom) in the periodic table. This is because as we move across a period, the effective nuclear charge increases, pulling electrons closer, making it harder to remove the outermost electron. Down a group, electrons are in higher energy levels (farther from the nucleus), so they are easier to remove.

Step2: Analyze positions of elements

• Element 1: Located in period 5, group 1 (alkali metals). Alkali metals have low IE as they readily lose one electron to achieve a noble gas configuration.
• Element 2: In period 4, group 6 (chalcogens). While IE increases across a period, it's in a lower period (4) compared to some others here.
• Element 3: In period 6, group 16 (chalcogens, lower period 6, so IE should be lower than elements in higher periods? Wait, no—wait, period number: higher period means lower IE (since electrons are farther). Wait, no: period 2 is higher (closer to top) than period 3, 4, 5, 6. Wait, let's correct: period 1 is top, period 7 is bottom. So element 4 is in period 2, group 16 (since group 16 is column 16, which is the 4th column from the right in the p - block? Wait, the periodic table: group 1 (leftmost), group 2, then transition metals (groups 3 - 12), then groups 13 - 18 (p - block). So group 16 is the 4th group from the right (18 - 16 = 2? Wait, group 13: 13, 14, 15, 16, 17, 18. So group 16 is the 4th column in the p - block (13 is 1st, 14 2nd, 15 3rd, 16 4th). So element 4 is in period 2, group 16. Element 3 is in period 6, group 16. Element 2 is in period 4, group 6. Element 1 is in period 5, group 1.

Now, let's list periods (top to bottom: period 1, 2, 3, 4, 5, 6, 7). So element 4 is in period 2, which is higher (closer to top) than periods 4, 5, 6. Element 2 is in period 4, element 1 in 5, element 3 in 6.

Across period 2: from left (group 1) to right (group 18), IE increases. Element 4 is in group 16, period 2. Let's compare with others:

• Element 4: period 2, group 16.
• Element 2: period 4, group 6. Even though group 6 is left of group 16, the period is lower (period 2 is higher than period 4? Wait, no—period 2 is above period 4. So element in period 2 is higher up (closer to top) than period 4. So element 4 is in a higher period (closer to top) and a more right - ward group (group 16 vs group 6 for element 2) than element 2.

Element 1: group 1, period 5—very low IE.

Element 3: period 6, group 16—lower IE than element 4 (since it's in a lower period? Wait, no—period 2 is higher (top) than period 6 (bottom). So element 4 is in a higher period (closer to top) and a more right - ward group (group 16) compared to others. So element 4 should have the highest first ionization energy among these four.

Answer:

Element 4