1s^2 2s^2 2p^6 3s^2 3p^64s^2
1s2 2s2 2p6 3s2 3p6 4s2
1s2 2s2 2p6 3s2 3p6
1s22s22p63s23p64s2
1s22s22p63s23p64s2.
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.
All of the representative elements (s and p block) have predictable electron configurations. However, many of the transition elements have electron configurations that are not predicted by the rules for determining electron configuration.
Group 18
halogens
The elements with the electron configurations that end in ns 2 and np 5 are halogens, group VII A elements.
Solutions are mixtures of one or more solutes dissolved in a solvent. They do not have electron configurations. Only atoms and ions have electron configurations.
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.
All of the representative elements (s and p block) have predictable electron configurations. However, many of the transition elements have electron configurations that are not predicted by the rules for determining electron configuration.
You don't. Calcium is not an electron, calcium is a element
Group 18
any time there are as many electrons and protons and they fill each orbital optimally.
The externall shell of electrons is completely filled.
The electron configuration of strontium is 1s22s22p63s23p63d104s24p65s2.
halogens
The elements with the electron configurations that end in ns 2 and np 5 are halogens, group VII A elements.
The elements with the electron configurations that end in ns 2 and np 5 are halogens, group VII A elements.
group 13 or IIIA