Question

1. based on the concept of periodic trends, answer the following questions for these atoms: li, be, mg, na. be able to defend your answers.

a which element has the lowest electronegativity? ____________
b which element has the least metallic character? ____________
c which element is the largest atom? ____________

Explanation:

Part a

Step1: Recall electronegativity trend

Electronegativity increases across a period (left to right) and decreases down a group (top to bottom) in the periodic table.

Step2: Locate elements in periodic table

Li (lithium) and Be (beryllium) are in period 2, group 1 and 2 respectively. Mg (magnesium) and Na (sodium) are in period 3, group 2 and 1 respectively.

Step3: Analyze electronegativity

Down a group (group 1: Li to Na), electronegativity decreases. Across a period (period 3: Na to Mg), electronegativity increases. So among Li, Be, Mg, Na, Na is in the lowest period (3) and leftmost group (1) among these, so it has the lowest electronegativity.

Step1: Recall metallic character trend

Metallic character decreases across a period (left to right) and increases down a group (top to bottom) in the periodic table.

Step2: Locate elements in periodic table

Li and Be are in period 2, Mg and Na in period 3.

Step3: Analyze metallic character

Across period 2 (Li to Be), metallic character decreases. Down group 2 (Be to Mg), metallic character increases. So Be is more to the right in its period and higher in its group compared to others, so it has the least metallic character.

Step1: Recall atomic size trend

Atomic size decreases across a period (left to right) and increases down a group (top to bottom) in the periodic table.

Step2: Locate elements in periodic table

Li (period 2, group 1), Be (period 2, group 2), Mg (period 3, group 2), Na (period 3, group 1).

Step3: Analyze atomic size

Down group 1 (Li to Na), atomic size increases. Down group 2 (Be to Mg), atomic size increases. Between Na (period 3, group 1) and Mg (period 3, group 2), Na is to the left, so larger. Between Li (period 2) and Na (period 3), Na is lower, so larger. So Na is the largest.

Answer:

Na

Part b