Answer: (A) The number of waves that pass a point in a certain amount of time.
Explanation:
Electromagnetic waves are categorized according to their frequency f or, equivalently, according to their wavelength λ = c/f. Visible light has a wavelength range from ~400 nm to ~700 nm.
Frequency: Is the number of waves that pass a certain point in a specified amount of time.
Trough: The low point of the wave cycle.
Wavelength: The distance between two successive peaks.
Electromagnetic wave: One of the waves that are propagated by simultaneous periodic variations of electric and magnetic field intensity.
The fiducial points of the Celsius<span> and the </span>Fahrenheit<span> temperature </span>scales<span> are the boiling and freezing </span>points<span> of pure water at 1 atm of pressure.
