Question

noble gas configuration

1. ar 4s²3d⁷:
2. he 2s²2p²:
3. xe 6s²:
4. he 2s¹:
5. kr 5s²4d²:
6. xe 6s²4f¹⁴5d¹⁰:

give full and noble gas (abbreviated) electron configurations for the following:
a. as full
noble gas
b. ti full
noble gas
c. si full
noble gas
d. al full
noble gas
e. kr full
noble gas
f. os full
noble gas

Explanation:

Step1: Recall noble - gas electron - configuration rules

Noble - gas configuration uses the nearest previous noble gas in brackets and then writes the remaining electron configuration. To find full electron configurations, we use the Aufbau principle, Pauli exclusion principle, and Hund's rule.

Step2: Identify elements from noble - gas configurations

1. For [Ar] 4s²3d⁷:

The atomic number of Ar is 18. Adding 2 (from 4s²) and 7 (from 3d⁷) gives 18 + 2+7 = 27. The element is Co (Cobalt).

1. For [He] 2s²2p²:

The atomic number of He is 2. Adding 2 (from 2s²) and 2 (from 2p²) gives 2 + 2+2 = 6. The element is C (Carbon).

1. For [Xe] 6s²:

The atomic number of Xe is 54. Adding 2 (from 6s²) gives 54 + 2=56. The element is Ba (Barium).

1. For [He] 2s¹:

The atomic number of He is 2. Adding 1 (from 2s¹) gives 2 + 1=3. The element is Li (Lithium).

1. For [Kr] 5s²4d²:

The atomic number of Kr is 36. Adding 2 (from 5s²) and 2 (from 4d²) gives 36+2 + 2=40. The element is Zr (Zirconium).

1. For [Xe] 6s²4f¹⁴5d¹⁰:

The atomic number of Xe is 54. Adding 2 (from 6s²), 14 (from 4f¹⁴) and 10 (from 5d¹⁰) gives 54+2 + 14+10 = 80. The element is Hg (Mercury).

Step3: Write full and noble - gas electron configurations for given elements

a. As (Arsenic, atomic number = 33)
Full: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p³
Noble gas: [Ar] 4s²3d¹⁰4p³
b. Ti (Titanium, atomic number = 22)
Full: 1s²2s²2p⁶3s²3p⁶4s²3d²
Noble gas: [Ar] 4s²3d²
c. Si (Silicon, atomic number = 14)
Full: 1s²2s²2p⁶3s²3p²
Noble gas: [Ne] 3s²3p²
d. Al (Aluminum, atomic number = 13)
Full: 1s²2s²2p⁶3s²3p¹
Noble gas: [Ne] 3s²3p¹
e. Kr (Krypton, atomic number = 36)
Full: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶
Noble gas: [Kr]
f. Os (Osmium, atomic number = 76)
Full: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d⁶
Noble gas: [Xe] 6s²4f¹⁴5d⁶

Answer:

1. Co
2. C
3. Ba
4. Li
5. Zr
6. Hg

a. Full: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p³, Noble gas: [Ar] 4s²3d¹⁰4p³
b. Full: 1s²2s²2p⁶3s²3p⁶4s²3d², Noble gas: [Ar] 4s²3d²
c. Full: 1s²2s²2p⁶3s²3p², Noble gas: [Ne] 3s²3p²
d. Full: 1s²2s²2p⁶3s²3p¹, Noble gas: [Ne] 3s²3p¹
e. Full: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶, Noble gas: [Kr]
f. Full: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d⁶, Noble gas: [Xe] 6s²4f¹⁴5d⁶