use the periodic table in the tools bar to complete the electron configurations for the following elements…

use the periodic table in the tools bar to complete the electron configurations for the following elements: lithium (li): 1s^a2s^b\na = \n\nb = \n\ndone
Answer
Explanation:
Step1: Determine lithium's atomic number
Lithium (Li) has an atomic number of 3, which means it has 3 electrons.
Step2: Fill the electron - shells
Electrons fill the 1s orbital first. The 1s orbital can hold a maximum of 2 electrons. So, for the 1s part of the electron - configuration, $A = 2$. Then, the remaining $3 - 2=1$ electron goes into the 2s orbital. So, $B = 1$.
Answer:
$A = 2$ $B = 1$