Please give answers only. No explanations or work shown isnecessary. A. An atom
ID: 688100 • Letter: P
Question
Please give answers only. No explanations or work shown isnecessary.A. An atom has the electron configuration 1s22s22p3how many valence electrons?
B. Write electron configurations for the following ions, anddetermine which have noble-gas configurations. (Type your answerusing the format [Ar] 4s2 3d10 4p2 for[Ar]4s23d104p2. If theconfiguration is a noble gas, enter the noble gas in brackets, forexample [Ne] for F -.) Here are a few examples
Se2- = [Kr]
Sc3+ = [Ar]
Tl+ = [Xe]6s24f145d10
(a) O2-
(b) Br -
(c) In2+
Explanation / Answer
A) 5 valence electrons B) O2- = [Ne] Br- = [Kr] In2+ = [Kr]5s14d10