Creating new elements in order to study their properties is definitely pure research.
It has no earthly [known] application, since the elements don't even exist, whereas
for each of the other choices, you've stated the desired application as the reason
for the search.
25 x 10^-5
= 0.00025
25 cm
= 0.00025 km
Answer:
(a). Index of refraction are
= 1.344 &
= 1.406
(b). The velocity of red light in the glass
2.23 ×
The velocity of violet light in the glass
2.13 ×
Explanation:
We know that
Law of reflection is

Here
= angle of incidence
= angle of refraction
(a). For red light
1 ×
=
× 
= 1.344
For violet light
1 ×
=
× 
= 1.406
(b). Index of refraction is given by

= 1.344


2.23 ×
This is the velocity of red light in the glass.
The velocity of violet light in the glass is given by

2.13 ×
This is the velocity of violet light in the glass.