【 】 1s2 2s2 2p6 3s2 3p5 ||What element has the electron configuration of 1s2 2s2 2p6 3s2 3p5 ?

 What is 1s2 2s2 2p6 3s2 3p5 ?

Answer:

1s2 2s2 2p6 3s2 3p5 means that 

●s subshell of first orbit or energy level has two electrons,

●s subshell of second orbit or energy level has two electrons,  

●p subshell of second orbit or energy level has six electrons,

●s subshell of third orbit or energy level has two electrons, 

● and p subshell of third orbit or energy level has five electrons.

Read:CO2 Lewis Structure



From 1s2 2s2 2p6 3s2 3p5 electron configuration,we get 2+2+6+2 + 5 = 17 electrons.


We know that electron's number is equal to proton number or atomic number for neutral atom.Since here there is no words about charge,we can say that 1s2 2s2 2p6 3s2 3p5 indicates the element whose atomic number is 17.


Now if you look at the periodic table,Cl has atomic number 17.

So 1s2 2s2 2p6 3s2 3p5 is electron configuration of Chlorine(Cl).

Read:CO2 Lewis Structure
 

Next

Read:CO2 Lewis Structure

Some Questions ans Answer:

An atom has the electron configuration 1s22s22p63s23p5. The electron dot symbol for this element is –

Answer:

From  the electron configuration of 1s22s22p63s23p5,we can see that this atom has 17 electrons.We know that in a neutral atom the number of electrons is equal to the number of protons.So this atom has 17 protons which indicates that this atom is chlorine whose atomic number is 17.

From  the electron configuration of the atom 1s22s22p63s23p5,we also see that its outermost shell is the third shell(3s23p5) and it has 7 valence electrons.

To draw the electron dot symbol or Lewis dot symbol of this atom,we need to only consider the valence electrons.

More Knowledge