The Lewis dot structure for potassium (K) is represented as:
- K with one dot around it: • K
This indicates that potassium has one valence electron in its outermost shell.
A. What is its Nuclear Charge?
The nuclear charge of an element refers to the total charge of the nucleus due to the presence of protons. Potassium has an atomic number of 19, which means it has 19 protons. Thus, its nuclear charge is +19. This positive charge attracts the negatively charged electrons, holding them in orbits around the nucleus.
B. How Many Inner Shell Electrons Does It Have?
Potassium has a total of 19 electrons. Since it has 1 valence electron (the outermost shell electron), we need to determine the number of electrons in the inner shells. The electron configuration of potassium is:
1s² 2s² 2p⁶ 3s¹
Counting the electrons in the inner shells:
- 1st shell: 2 electrons (1s²)
- 2nd shell: 8 electrons (2s² and 2p⁶)
In total, the inner shells have 2 + 8 = 10 electrons. Therefore, potassium has 10 inner shell electrons.