Q. 4.108 - An Introduction to General, Organic, and Biological Chemistry

Question

Write the group number and the electron arrangement for each of the following: $(4.6)$

a. Magnesium

b. Chlorine

c. Beryllium

d. Argon

Step-by-Step Solution

Answer

a. The group number is $2A$ and electron arrangement is $2,8,2$.

b. The group number is $7A$ and electron arrangement is $2,8,7$ . 

c. The group number is $2A$ and electron arrangement is $2,2$. 

d. The group number is $8A$ and electron arrangement is $2,8,8$.

Part (a) step 1: Given Information

We need to find the group number and the electron arrangement.

Part (a) step 2: Explanation

According to the periodic table, Magnesium belongs in Group $2A$.

It is started in the periodic table that it has an atomic number of $12$. For an electron arrangement, the first two electrons would fill the first energy level. Then, the order of eight electrons would fill the second energy level. The two remaining electrons would occupy the third energy level. So, Magnesium $2,8,2$.

Part (b) step 1: Given Information

We need to find the group number and the electron arrangement.

Part (b) step 2: Explanation

According to the periodic table, Chlorine belong in Group $7A$.

It is started in the periodic table that it has an atomic number of  $17$. For an  electron arrangement, the first two electrons would fill the first energy level. Then, the order of eight electrons would fill the second energy level. The seven remaining electrons would occupy the third energy level. So, Chlorine $2,8,7$.

Part (c) step 1: Given Information

We need to find the group number and the electron arrangement.

Part (c) step 2: Explanation

According to the periodic table, Beryllium belong in Group $2A$.

It is started in the periodic table that it has an atomic number of  $4$. For an  electron arrangement, the first two electrons would fill the first energy level. Then, the order of two electrons would fill the second energy level. So Beryllium $2,2$.

Part (d) step 1: Given Information

We need to find the group number and the electron arrangement.

Part (d) step 2: Explanation

According to the periodic table, Argon belong in Group  $8A$.

It is started in the periodic table that it has an atomic number of $18$. For an  electron arrangement, the first two electrons would fill the first energy level. Then, the order of eight electrons would fill the second energy level. The eight remaining electrons would occupy the third energy level. So, Argon $2,8,8$.