Pls 1. how many valence electrons are in an atom with the electron configuration in example a? example a: 1s22s22p63s23p64s24p2 22 2 4 62. the d subshell can hold up to 10 electrons in an atom. true false3. fill in the blank- the element argon has valence electrons. (input only a whole number, such as 7.)

Answer 1: there are 4 valence electrons in the Example A

Answer 2:  The d subshell can hold up 10 electron: True

Answer 3: The element argon has 8 valence electrons.

Explanation:

Answer 1: The example A has four shells, and in the forth shell, it holds a total of  2 + 2 = 4 , so it has  4  valence electrons.

Answer 2: As you can see in the image, the d subshell has 5 different areas where you likely find a pair of electrons. In each area you can find until 2 electrons, so 5 x 2 = 10 electrons can be hold up in the  d subshell.

Answer 3: Noble gases like argon have 8 valence electrons and its electron configuration is  [ N e ] 3 s 2 3 p 6  

it's c. elements are placed in rows based on how may valencies electrons have.