Answer:
The wavelength in vacuum is equal to 428.8 nm.
Explanation:
Given that,
The wavelength of light, 
The refractive index of glass, n = 1.51
We need to find the wavelength in vacuum. The relation between wavelength and refractive index is given by :

So, the wavelength in vacuum is equal to 428.8 nm.
We r made of atom so v can’t touch anything hehe I just joking
The transfer of energy that occurs when a force is applied over a distance is WORK.
<span>The cation is positively charged and has a charge twice that of the anion, for example +2.
The anion is negatively charged and in our example where the cation has a +2 charge, it must have a -1 charge.
In order for the charges to equal zero, there must be two anions: -1 x 2 = -2
So the answer is D. AX2</span>
Helium, neon and Xeon belong to the same Column( Group) which is Column 18 or you can say Group 8 in roman numbers
don't forget if you say group you should write in roman numbers okay. Best of luck