both the questions plzzzzzzzzzzz

Answers
Answer:
for question 68.
Z atomic no is 30
Explanation:
write electronic configuration.
3p and 4s has 6 and 2 electrons respectively
67)U already calculated values of n1 and n2 in exm probably n1=2 and n2=6.Now u need to know the energy diff. btwn n1 nd n2.U can easily find it if u remember the values for diffm energy levels.Rememer till 4th or 5th enrgy level and higher ones u can calculate using -13.6z^2/n^2.Now equate this enrgy diff. u calcluted as delE=nhc/lambda but here is the point....u hv to convert the delE u calculated into JOULE as nhc/lambda is in si units.U will get the answer!!!
68)isko ese kr skti ho.We need only those elec. which have n+l=4 so,
n + l
0 4 (in Zn there is no morr than d
subshell i.e. l=2 so 1st option
wrong)
1 3 (again same reason)
2 2 (this time l is 2 but n is also 2
and ther is no 2d but only 3d
so not possible)
3 1 ( this is possible as 3p is
available nd has 6 elec.)
4 0 (this is also possible as 4s is
is available nd has 2 electrons)
So n+l=4 is applicable for a total of 6+2= 8 electrons.Hope i made it clear!!!