The following electron configurations represent excited states Identify the element
(a) 1s2 2s2 3p2 4p1,
(b) [Ar] 3d10 4s1 4p4 5s1,
(c) [Kr] 4d65s25p1.
The Correct Answer and Explanation is :
Let’s break down the electron configurations for each case and identify the elements.
(a) 1s² 2s² 3p² 4p¹
This configuration consists of:
- 1s² (2 electrons)
- 2s² (2 electrons)
- 3p² (2 electrons)
- 4p¹ (1 electron)
First, let’s count the total number of electrons: 2 + 2 + 2 + 1 = 7 electrons. This corresponds to nitrogen (N) in the 3rd period. The 3p² electrons show an excited state, meaning one of the 3p electrons has been promoted to a higher energy level. The element is gallium (Ga), as this configuration corresponds to its excited state.
(b) [Ar] 3d¹⁰ 4s¹ 4p⁴ 5s¹
This configuration consists of:
- [Ar] (argon core, representing the first 18 electrons)
- 3d¹⁰ (10 electrons in the 3d orbital)
- 4s¹ (1 electron in the 4s orbital)
- 4p⁴ (4 electrons in the 4p orbital)
- 5s¹ (1 electron in the 5s orbital)
Counting these, we get: 18 (from Argon) + 10 (from 3d) + 1 (from 4s) + 4 (from 4p) + 1 (from 5s) = 34 electrons. This corresponds to the element selenium (Se), which has atomic number 34. The excited state is reflected in the 4s and 5s electron promotions.
(c) [Kr] 4d⁶ 5s² 5p¹
This configuration consists of:
- [Kr] (krypton core, representing the first 36 electrons)
- 4d⁶ (6 electrons in the 4d orbital)
- 5s² (2 electrons in the 5s orbital)
- 5p¹ (1 electron in the 5p orbital)
Counting the electrons: 36 (from Kr) + 6 (from 4d) + 2 (from 5s) + 1 (from 5p) = 45 electrons. This corresponds to rhodium (Rh), which has atomic number 45.
Summary of Results:
(a) Gallium (Ga)
(b) Selenium (Se)
(c) Rhodium (Rh)
Now, let me generate an image representing these electron configurations for you.
Here’s an illustration showing the electron configurations for Gallium (Ga), Selenium (Se), and Rhodium (Rh). It visually represents the energy levels, orbitals, and electron placements for each element’s excited state. Let me know if you’d like more details!
