Answer:
D. are brought from the mantle to the surface in magma that hardens into komatiite.
Explanation:
Diamond :
It is the hardest form of carbon.The atomic atoms arrange in the cubic crystal structure and this is known as diamond cubic.Another form of the diamond at room temperature is graphite.This is used for making jewelry.This is also used in the cutting process because it has high strength.
Therefore the correct option for the diamond is D.
Answer:
Option B
Explanation:
Speed of a wave is denoted by:
v=fλ
where f is the frequency which is unchanged 15Hz and λ is the new wavelength which is 28m
v=fλ

Explanation: Newton's first law of motion states that a body at rest remains at rest, or, if in motion, remains in motion at a constant velocity unless acted on by a net external force. This is also known as the law of inertia. Inertia is the tendency of an object to remain at rest or remain in motion.
A. through a relatively short distance.
The speed is actually called the drift speed of the electron.