Predict the ground-state electron configuration of the following ions. Write your answers in abbreviated form, that is, beginnin

Question

Ksju [112]

3 years ago

12

Predict the ground-state electron configuration of the following ions. Write your answers in abbreviated form, that is, beginnin

g with a noble gas in brackets.a). Cr2+b.)Cu2+c.)Co3+

Chemistry

1 answer:

abruzzese [7] · Answer 1 · 2022-02-06T21:30:54+03:00

These are three questions and three complete answers

Answer:

a) Cr²⁺: [Ar] 4s² 3d²

b) Cu²⁺: [Ar] 4s² 3d⁷

c) Co³⁺: [Ar] 4s² 3d⁴

Explanation:

a) Cr²⁺

Z = 24

Number of protons: 24

Number of elecrons of the neutral atom: 24

Charge of the ions: + 2

Number of electrons of the ion: 24 - charge = 24 - 2 = 22.

Electron configuration:

Fill the orbitals in increasing order of energy. Using Aufbau's rules the order is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ .....

Hence, for 22 electrons you get:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d²

Abbreviated notation: since the last complete level is the number 3s² 3p⁶, you use the noble gas of the period 3, which is Ar, and the configuration is:

[Ar] 4s² 3d²

b) Cu²⁺

Z = 29

Number of protons: 29

Number of elecrons of the neutral atom: 29

Charge of the ion: + 2

Number of electrons of the ion: 29 - charge = 29 - 2 = 27.

Electron configuration:

Fill the orbitals in increasing order of energy. Using Aufbau's rules the order is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ .....

Hence, for 27 electrons you get:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁷

Abbreviated notation: since the last complete level is the number 3s² 3p⁶, you use the noble gas of the period 3, which is Ar, and the configuration is:

[Ar] 4s² 3d⁷

c) Co³⁺

Z = 27

Number of protons: 27

Number of elecrons of the neutral atom: 27

Charge of the ion: + 3

Number of electrons of the ion: 27 - charge = 27 - 3 = 24.

Electron configuration:

Fill the orbitals in increasing order of energy. Using Aufbau's rules the order is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ .....

Hence, for 24 electrons you get:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁴

Abbreviated notation: since the last complete level is the number 3s² 3p⁶, you use the noble gas of the period 3, which is Ar, and the configuration is:

[Ar] 4s² 3d⁴