Long-hand version: 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 Short-hand version: [Ne] 4s^2 Note: The "^" symbol means the the following number is in the form of a superscript.
Li, Be, O: the first term in the abridged electron configuration is [He]. Ca, K: the first term in the abridged electron configuration is [Ar].
Normal Ca atom electron configuration: 1s2 2s2 2p6 3s2 3p6 4s2Ca+ (last electron is gone from the s orbital): 1s2 2s2 2p6 3s2 3p6 4s1
Calcium loses two electrons to obtain a noble-gas electron configuration.
1s2 2s2 2p63s23p64s2
No Such ... all atoms have an electron configuration, yet Ca++ is not a noble gas.
Ca {1s2 2s2 2p6 3s2 3p6 4s2 }
It can't sowwy
Calcium, or Ca
Cl- and Ca2+ has the electronic configuration of the noble gas, Ar, with 18 electrons.
The element calcium, or Ca, is located in group 2, period 4 of the periodic table. Therefore, its electron configuration is 1s2 2s2 2p6 3s2 3p6 4s2. This can also be written as [Ar] 4s2, because the beginning of that electron configuration is the same as argon's. The 42 you mentioned in your question is referring to a specific isotope of calcium and has nothing to with the electron configuration.
The electron configuration is the number of electrons in each energy level of an element. The electron configuration of Li is, 1s2 2s1. The electron configuration of F is, 1s2 2s2 2p5.
The electron configuration for oxygen is [He]2s2.2p4.The electron configuration for sulfur is [Ne]3s2.3p4.