Question

Four elements A, B, C and D have atomic no. 12,13,14 and 15 respectively. Answer the following questions giving reasons -
1. What is the no. Of valence electrons and valency of D.
2. Which of them will have largest atomic radii.
3. Which of the following will form most basic oxide.

Answer 1

Answer:

a. valence electrons is 5 and valency is 3.

b. A will have a larger atomic radii.

c. A will form the most basic oxide.

Explanation:

a. element D has 5 electrons in its outter shell and needs 3 more to complete its noble gas configration.

b. A has larger radii because it has less electrons there fore the nuclear charge which pulls the electrons closer to it is low and thus the atomic radii is more while in other element B C and D the nuclear charge is more and the nucleous tends to pull the electrons closer there fore this elements have a smaller atomic radii.

C. As we know metals form basic oxides and the most metalic here is A because metals has a tendency to loose electrons.... and as number of electrons increases the element becomes less metalic.

Answer 2

Answer:

$valence \: electron \: 5 \: and \: valency \: 3. \\ a \: will \: have \: largest \: radii. \\ a \: will \: form \: the \: basic \: oxide$