Answer:
26.6°
Explanation:
refractive index of diamond, n = 2.23
When a ray of light passes from denser medium to the rarer medium and refracts at an angle of 90 degree from the normal of the surface, such angle of incidence in the denser medium is called the critical angle.
By the Snell's law

For critical angle, angle of incidence is critical angle, i = θc and angle of refraction, r = 90
So,
Sin θc / Sin 90 = 1 / 2.23
Sin θc = 0.448
θc = 26.6°
Thus, the critical angle is 26.6°.
Exactly the same way that you can photograph a mountain or a skyscraper
with the itty bitty camera in your smartphone.
Lenses are used to form a tiny image of a gigantic object.
Because a galaxy is a large collection of many stars, and almost every star radiates some visible light.
Answer:
Option B
Explanation:
The correct answer is Option B.
Before Moseley's discovery in 1913, In Mendeleev's periodic table the elements rearranged with increasing atomic mass.
Mendeleev was not able to locate hydrogen atom and late isotopes found violate Mendeleev table. The biggest drawback was that the atomic mass was not regular when moving one element to another.
But Moseley's arranged element in the periodic table with increasing atomic number.
No. Motion is the thing that when you're moving, you're in it.
But it IS possible for one person to say you're moving and another person to say you're not moving, both at the same time, and both of them are correct !