Class 12th

I = P/ (4πr²) . (i)
and I = (1/2)ε? E? ²c . (ii)
From (i) and (ii)
P/ (4πr²) = (1/2)ε? E? ²c
E? = √ (2P/ (4πε? r²c) ; E? = √ (9*10? *2*15)/ (15*15*10? *3*10? ) = 2*10? ³ V/m

$AgC\mathcal{l}+2N{H}_3\to \underset{\left(Solublecomplex\right)}{\left[Ag{\left(N{H}_3\right)}_2\right]C\mathcal{l}}$

R? = (ρ? L)/a² R? = (ρ? L)/ (3a²)
Both are in parallel . R? = (R? )/ (R? +R? ) = (ρ? ρ? L)/ (a² (3ρ? +ρ? )

Blue cupric metaborate is reduced to cuprous metaborate in a luminous flame.

$2Cu{\left(B{O}_2\right)}_2+2NaB{O}_2+C\underset{}{\overset{Luminous}{\to }}2CuB{O}_2+N{a}_2{B}_4{O}_7+CO$            

Cupric metaborate is obtained by heating boric anhydride & copper sulphate in a non-luminous flame as

$CuS{O}_4+B_2{O}_3\underset{}{\overset{Non-LuminiousFlame}{\to }}\underset{Blue}{Cu{\left(B{O}_2\right)}_2}+S{O}_3.$            

µ = A? /A? = 0.5 {A? = 20 volt, A? = 40 volt}
m (t) = A? sin ω? t {ω? = 2π*10? }
c (t) = A? sin ω? t {ω? = 2π*10*10³}
C? (t) = (A? + A? sin ω? t) sin ω? t ⇒ A? {1+ µsin ω? t} sin ω? t

Size of hydrated ion $$ $\propto$ $\frac{1}{Ionicmobility}$ $\frac{}{}$

Size of hydrated ions $\propto \frac{1}{Ionicsize}$ $\frac{}{}$

Size of hydrated ions ;  $B{e}^{+2}>M{g}^{+2}>C{a}^{+2}>S{r}^{+2}$ ${}^{}{}^{}{}^{}{}^{}$

Ionic mobility ; $B{e}^{+2}<M{g}^{+2}<C{a}^{+2}<S{r}^{+2}$

(hc/λ) = 13.6Z² (1/1² - 1/4²) = 13.6Z² (3/4) ; [λ = (4/3)k]

β line of Paschen
(hc/λ') = 13.6Z² (1/9 - 1/25)
λ = k * (9*25/16) ; λ' = (3/4)λ * (9*25/16) = (3³*5²/2? )λ

Cu is the only element of 3d – series whose M²⁺ / M value is positive because of fact that low hydration enthalpy and high sublimation & ionization enthalpies.