Question

1. what is the abbreviated ground state electron configuration for iron?

a) ar 3d⁶ 4s²
b) ar 3d⁸ 4s⁰
c) kr 3d⁶ 4s²
d) ar 3d⁶ 4e⁻

1. which of the following is the correct complete ground state electron configuration for calcium?

a) 1s²2s²2p⁶3s²3p⁶4s²
b) 1s²2s²2p⁶3s²3p⁶4s¹
c) 1s²2s²2p⁶3s²3p⁶
d) 1s²2s²2p⁶3s²3p⁶4s⁰

1. which of the following is the correct complete ground state electron configuration for titanium?

a) 1s²2s²2p⁶3s²3p⁶4s²3d²
b) 1s²2s²2p⁶3s²3p⁶4s¹3d³
c) 1s²2s²2p⁶3s²3p⁶4s⁰3d⁴
d) 1s²2s²2p⁶3s²3p⁶4s²3d⁰

1. which element has the abbreviated ground state electron configuration xe 6s²4f¹⁴5p⁶?

a) polonium
b) barium
c) lead
d) erbium

1. which element has the complete ground state electron configuration 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²?

a) rubidium
b) calcium
c) lead
d) erbium

1. identify the element with the electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹.

a) calcium
b) potassium
c) magnesium
d) sodium

1. identify the element with the electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p¹.

a) gallium
b) zinc
c) germanium
d) arsenic

Explanation:

Question 7

Step1: Find atomic number of Fe

Iron (Fe) has atomic number 26.

Step2: Locate noble gas core

The preceding noble gas is Argon (Ar, Z=18).

Step3: Fill remaining electrons

26-18=8 electrons. Fill 3d first (lower energy than 4s for transition metals), then 4s: $3d^6 4s^2$.

Step1: Find atomic number of Ca

Calcium (Ca) has atomic number 20.

Step2: Fill orbitals in Aufbau order

Fill 1s, 2s, 2p, 3s, 3p, 4s: $1s^2 2s^2 2p^6 3s^2 3p^6 4s^2$.

Step1: Find atomic number of Ti

Titanium (Ti) has atomic number 22.

Step2: Fill orbitals in Aufbau order

Fill 1s, 2s, 2p, 3s, 3p, 4s, then 3d: $1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^2$.

Answer:

a) [Ar] $3d^6 4s^2$

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Question 8