Question

If the following elements were to form ions, they would attain the same number of electrons as which noble gas? As , Be , O , S , Ca , Mg , Sr

Answer 1

Answer;

As, & Sr --------[Kr]

Be ------------------- [He]

O, & Mg ----------[Ne]

S, & Ca -------------[Ar]

Explanation

• The Be+ ion has 2 electrons, just like He. The ions Mg2+ and O2− each has 10 electrons like Ne.
• The S2− and Ca2+ each has 18 electrons like Ar. The ions As3− and Sr+ each have 36 electrons like Kr.
• Atoms of elements lose or gain electrons to attain a stable configuration which is equivalent to the configuration of noble gases.
• When atoms lose or gain electrons they form ions, which are either positively charged or negatively charged. When atoms lose electrons they form positively charged ions while if they gain electrons the form negatively charged ions

Answer 2

As would attain same electrons as that of Kr after formation of ion.

Be would attain same electrons as that of He after formation of ion.

O would attain same electrons as that of Ne after formation of ion.

S would attain same electrons as that of Ar after formation of ion.

Ca would attain same electrons as that of Ar after formation of ion.

Mg would attain same electrons as that of Ne after formation of ion.

Sr would attain same electrons as that of Kr after formation of ion.

Further explanation:

Electrons are distributed in various atomic orbitals of an atom in accordance with certain rules and principles. These are described below:

1. Aufbau principle

“Aufbau” is a German word that implies “build up”. So this principle states that the electrons are filled in various orbitals in the increasing order of their energies. The atomic orbitals have the following energy order:

$1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s < 4f < 5d < 6p < 7s < 5f < 6d < 7p$  

2. Hund’s rule

This rule states that electron pairing will never begin until each orbital is singly occupied.

3. Pauli’s exclusion principle

According to this principle, no two electrons in the same orbital can have all the four quantum numbers same. The value of spin quantum number for both electrons in the same orbital must always be different.

Ions are formed by the addition or removal of electrons from the neutral atom. Anions are produced when there is gain of electrons by the neutral atom whereas cation formation takes place by the removal of electrons from the neutral atom.

The atomic number of As is 33 so its configuration is $\left[ {{\text{Ar}}} \right]3{d^{10}}4{s^2}4{p^3}$. It gains three electrons to form ${\text{B}}{{\text{e}}^{2 + }}$ whose configuration becomes $1{s^2}$. This configuration is similar to that of krypton. So As would attain same electrons as that of Kr after formation of ion.

The atomic number of Be is 4 so its configuration is $1{s^2}2{s^2}$. It loses two of its 2s electrons to form ${\text{B}}{{\text{e}}^{2 + }}$ whose configuration becomes $1{s^2}$. This configuration is similar to that of helium. So Be would attain same electrons as that of He after formation of ion.

The atomic number of O is 8 so its configuration is $1{s^2}2{s^2}2{p^4}$. It gains two electrons to form ${{\text{O}}^{2 - }}$ whose configuration becomes $1{s^2}2{s^2}2{p^6}$. This configuration is similar to that of neon. So O would attain same electrons as that of Ne after formation of ion.

The atomic number of S is 16 so its configuration is $1{s^2}2{s^2}2{p^6}3{s^2}3{p^4}$. It gains two electrons to form ${{\text{S}}^{2 - }}$ whose configuration becomes $1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}$. This configuration is similar to that of argon. So S would attain same electrons as that of Ar after formation of ion.

The atomic number of Ca is 20 so its configuration is $1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}4{s^2}$. It loses two of its 4s electrons to form ${\text{C}}{{\text{a}}^{2 + }}$ whose configuration becomes $1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}$. This configuration is similar to that of argon. So Ca would attain same electrons as that of Ar after formation of ion.

The atomic number of Mg is 12 so its configuration is$1{s^2}2{s^2}2{p^6}3{s^2}$. It loses two of its 3s electrons to form   whose configuration becomes ${\text{M}}{{\text{g}}^{2 + }}$. This configuration is similar to that of neon. So Mg would attain same electrons as that of Ne after formation of ion.

The atomic number of Sr is 38 so its configuration is $1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}3{d^{10}}4{s^2}4{p^6}5{s^2}$. It loses of its 5s electrons to form   whose configuration becomes $1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}3{d^{10}}4{s^2}4{p^6}$. This configuration is similar to that of krypton. So Sr would attain same electrons as that of Kr after formation of ion.

Learn more:

1. Determine the ion with configuration $\left[ {{\text{Ar}}} \right]\;3{d^2}$: brainly.com/question/7599542
2. Identification of element which has electron configuration  :brainly.com/question/9616334

Answer details:

Grade: High School

Subject: Chemistry

Chapter: Electronic configuration of the elements

Keywords: Ca, Mg, Sr, Be, O, As, Kr, He, Ne, 8, 20, 33, 38, 12, 4, configuration, Aufbau principle, Hund’s rule, Pauli’s exclusion principle, distribution of electrons.