There are some methods that differentiate waves; one thing is by its medium.
Electromagnetic waves did not require a medium for transmission such as in a
vacuum while mechanical waves require a medium to travel such as air, water or
anything that can serve as a transmission aid.
The most common sample of EM waves in
telecommunication is radio,
light and infra-red signals. An example of a mechanical wave is a sound
wave, which requires air to travel. Oscillating molecules made the
sound waves.
Answer: A. Energy was absorbed
Answer:
Explanation:
Depression in freezing point is given by:

= Depression in freezing point
i= vant hoff factor = 1 (for non electrolyte like urea)
= freezing point constant = 
m= molality

Weight of solvent (X)= 950 g = 0.95 kg
Molar mass of non electrolyte (urea) = 60.06 g/mol
Mass of non electrolyte (urea) added = ?


Thus
urea was dissolved.
Bleach, laundry detergent.
Valence shell it contains the valence electrons e.g. the outermost electro