For Be, Z effect =1.95 and for Be^+x,Z effect=2.30,hence icon is
Answers
Answer:
Effective nuclear charge Z
eff
=Z−S
where Z = atomic number
and S = screening constant
= 0.35 per electron for electron in n
th
orbit.
= 0.85 per electron for electrons in(n−1)
th
orbit
= 1.00 per electron for electrons in (n−2)
th
, (n−3)
th
,(n−4)
th
orbit
= 0.30 per electron in 1s-orbital (when alone)
Be= 1s
2
2s
2
one valence-electron in 2s is screened by one electron in 2s−orbital (n
th
orbit) and two electrons in 1s orbital ((n−1)
th
orbit)
∴S=0.35+2×0.85=2.05
∴Z
eff
=4−2.05=1.95 (given)
Be
+
:1s
2
2s
1
,2s-electron is screened by two electrons in 1s-orbital ((n−1)
th
orbital)
S=2×0.85=1.70
∴Z
eff
=4−1.70=2.30
Be
2+
:1s
2
one electron in 1s-orbital (alone exists) is screened by another electron in same orbit. Thus,
S=0.30
∴Z
eff
=4−0.30=3.70
Be
3+
:1s
1
no-screening (single electron)
Thus, Z
eff
Answer:
Ion is Be+
Hope it helps!