Answer:
(a) [Noble gas] ns² np⁵: Number of unpaired electron is 1 and belongs to group 17 i.e. halogen group of the periodic table.
(b) [noble gas] ns² (n-1)d²: Number of unpaired electron is 2 and belongs to group 4 of the periodic table.
(c) [noble gas] ns² (n-1)d¹⁰ np¹: Number of unpaired electron is 1 and belongs to group 13 of the periodic table.
(d)[noble gas] ns² (n-2)f⁶ : Number of unpaired electron is 6 and belongs to group 8 of the periodic table.
Explanation:
In the Periodic table, the chemical elements are arranged in 7 rows, called periods and 18 columns, called groups. They are organized in increasing order of atomic numbers.
(a) [Noble gas] ns² np⁵
As the total number of electrons in the p-orbital is 5. Therefore, the number of unpaired electron is 1.
This element has 2 electrons in ns orbital and 5 electrons in np orbital. <u>So there are 7 valence electrons.</u>
Therefore, this element belongs to the group 17 i.e. halogen group of the periodic table.
(b) [noble gas] ns² (n-1)d²
As the total number of electrons in the d-orbital is 2. Therefore, the number of unpaired electrons is 2.
This element has 2 electrons in ns orbital and 2 electrons in (n-1)d orbital. So there are <u>4 valence electrons.</u>
Therefore, this element belongs to the group 4 of the periodic table.
(c) [noble gas] ns² (n-1)d¹⁰ np¹
As the total number of electrons in the p-orbital is 1. Therefore, the number of unpaired electron is 1.
This element has 2 electrons in ns orbital and 1 electron in np orbital. So there are <u>3 valence electrons</u>.
Therefore, this element belongs to the group 13 of the periodic table.
(d)[noble gas] ns² (n-2)f⁶
As the total number of electrons in the f-orbital is 6. Therefore, the number of unpaired electron is 6.
This element has 2 electrons in ns orbital and 6 electrons in (n-2)f orbital. So there are <u>8 valence electrons.</u>
Therefore, this element belongs to the group 8 of the periodic table.
= 0.0151 mol Na₂CO₃