Determine the total number of electrons, the number of valence electrons, and the name of the element with each electronic configuration. 1s2, 2s1
The electronic configuration 1s2, 2s1 represents an atom with 3 electrons.
To determine the number of valence electrons, we look at the outermost energy level (the highest value of n). In this case, the outermost energy level is 2, and there is 1 electron in the 2s sublevel. Therefore, the number of valence electrons is 1.
Based on the electronic configuration, we can identify the element as lithium (Li).