Answer:
B
Explanation:
Wave length is the height perpendicular verically of a wave
Explanation:
Half-life is the time taken for a radioactive material to decay to half its original composition:
Original mass = 48g
Half- life = 2hr
After four half lives;
Initially: 48g
First halving 24
Second halving 12
Third halving 6
Fourth halving 3
After second half life, we would have 12g
At fourth halving, we would have 3g
Answer:

Explanation:
n = Order = 1
c = Speed of light = 
f = Frequency = 
= Angle = 
Lattice spacing is given by

The lattice spacing of the crystal is 
Answer:
Refractive motion is the impact of a light wave that travels from medium to medium in an angle away from normal, where the direction of light varies. Light is refracted when it crosses the air-to-glass interface and moves slower.
Explanation:
Refractive motion is the impact of a light wave that travels from medium to medium in an angle away from normal, where the direction of light varies. Light is refracted when it crosses the air-to-glass interface and moves slower.
Hope this helps.