[He] 2s1
1s22s1
[He] 2s1
There are four electrons in a Beryllium atom. Hence the mono positive ion has only three electrons. Therefore the electron configuration is 1s2 2s1.
the electron dot structure for lithium is Li ' (the element symbol with one dot on the upper right side)
Lithium (Li) has the electron configuration 1s2 2s1.
[He]2S1
1s2, 2s1
[He] 2s1
The electronic structure of lithium (Li) is 1s2 2s1, indicating that it has 3 electrons. The first shell is filled with 2 electrons in the 1s orbital, and the remaining electron is in the 2s orbital of the second shell.
[He] 2s1
1s22s1
[He] 2s1
[He] 2s1
[He] 2s1
Could be lithium (ends with 2s1) or beryllium (2s2)
The abbreviated electron configuration of lithium is [He] 2s1.