An element "E" is present as 10E with a mass value of 10.01 amu, and as 11E with a value of 11E amu. The natural abundances of 10E and 11E are 19.78% and 80.22% respectively. What is the average atomic mass of the element? What is the element?

the answer is true.

this statement is true.

The answer is 1.82 j/g°c                  

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.

The formula is (nh4)2co3