Questions

Hybridisation of Ni is e-  

Unpaired 3d8in  is 2 

So $$\begin{gathered} Ω = n(n+2)BM \\ =2x4 = 8 = 2.82BM \end{gathered}$$

Because the refractive index of glass is highest, light travels slowly in Glass. 

We know that the speed of light depends on the refraction index. The higher the index of refraction is, the slower the speed of light is.

R.I of air and vacuum = 0 (air is a teeny bit more but can be taken as 0)
R.I of water = 1.33
R.I of glass = 1.4.

Hence, Light travels slowest in Glass.

The Union Minister for Science & Technology Dr. Harsh Vardhan has launched a mobile app “Celebrating Yoga” in New Delhi to connect people through Yoga for scientific healthy living. The mobile app has been developed by Department of Science & Technology on the occasion of International Yoga Day (IYD) 2017. The aim of the app is to popularize Yoga and encourage people to practice yoga for a scientifically healthy living.