The following table shows the position of five elements A, B, C, D an the modern periodic table.
1
2
3 to 12 13
Group
Period
14
15
16
17.
18
2
A
B
C с
3
D
E
Answer the following giving reasons:
(1) Which element is a metal with valency two?
(ii) Which element is least reactive?
(111) Out of D and E which element has a smaller atomic radius?​

Achemistry student needs to standardize a fresh solution of sodium hydroxide. he carefully weighs out of oxalic acid , a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in of distilled water. the student then titrates the oxalic acid solution with his sodium hydroxide solution. when the titration reaches the equivalence point, the student finds he has used of sodium hydroxide solution.calculate the molarity of the student's sodium hydroxide solution. be sure your answer has the correct number of significant digits.