A. Condensation
Hope this helps!!!
Answer:

Explanation:
By Einstein's Equation of photoelectric effect we know that

here we know that
= energy of the photons incident on the metal
= minimum energy required to remove photons from metal
= kinetic energy of the electrons ejected out of the plate
now we know that it requires 351 nm wavelength of photons to just eject out the electrons
so we can say

here we know that

now we have

now by energy equation above when photon of 303 nm incident on the surface





Answer:
True
Explanation:
Convection is a form of heat transfer that is predominantly common in fluids especially liquid and gas.
It occurs by the movement of a part of substance from one place to another based on density and temperature differences.
A typical convection cell is made up of a liquid that is heated. The liquid part close to the heat source becomes warmer and rises due to its low density. The part away from the heat source is more dense and begins to sink.
This analogy is commonly demonstrated in a boiling pot of water.
Average speed=total distance travelled/time
If the girl is also near the source of the sound, two alike sets of sounds will be heard.