Element X and Y have the following electronic configurations (X and Y are not the correct symbols of the elements.) х
Y
2,8,2
2.8.8.2
What is the atomic number of Element Y?

20

Explanation:

The atomic number tells you the amount of electrons and protons in an atom so if you add all of the electrons up (2+8+8+2) you get 20.

for points guys

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"