Which of the following elements is the most electropositive?

• A. Al
• B. Na
• C. Mg
• D. K

Answer: (D)

Verified step by step guidance

1. Understand the concept of electropositivity: Electropositivity refers to the tendency of an element to lose electrons and form positive ions (cations). Elements that are more electropositive tend to be metals located on the left side and towards the bottom of the periodic table.
2. Identify the elements given in the problem: Aluminum (Al), Sodium (Na), Magnesium (Mg), and the correct answer given is Potassium (K). Note that Potassium (K) is not listed in the options but is mentioned as the correct answer.
3. Locate each element on the periodic table: Sodium (Na) and Potassium (K) are in Group 1 (alkali metals), Magnesium (Mg) is in Group 2 (alkaline earth metals), and Aluminum (Al) is in Group 13. Potassium is below Sodium in the same group, meaning it has more electron shells.
4. Recall the trend of electropositivity in the periodic table: Electropositivity increases as you move down a group because atoms have more electron shells, making it easier to lose the outermost electron. It decreases as you move from left to right across a period.
5. Compare the elements based on their position: Since Potassium (K) is below Sodium (Na) in Group 1, it is more electropositive than Sodium, Magnesium, and Aluminum. Therefore, Potassium is the most electropositive element among the ones mentioned.