Answer : A
Explanation : Surface-active compounds/agents (surfactants) Substances which have the effect of reducing the surface tension of a solvent, an example being a detergent/surfactant or soap dissolved in water. ... Both synthetic detergents and soaps are surfactants. Surfactants See "Surface-active compounds/agents".
•A wave produced by the acceleration of an electric charge and propagated by the periodic variation of intensities of, usually, perpendicular electric and magnetic fields
In other words : They are radio waves, microwaves, visible light, and x rays are all examples of electromagnetic waves
They are produced by the motion of electrically charged particles.
I hope this helped ! :)
The humidity of yesterday was grater than today`s there has been percipitation and also a lot of air pressure
Answer: The moles of melatonin are 0.000043
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number 
of particles.
To calculate the moles, we use the equation:
Given mass of melatonin = 0.01 g
Molar mass of melatonin 
= 232.28 g/mol
Thus the moles of melatonin in 0.01 g are 0.000043
