Copper wire is not an example of a pure element because although it's made by pure elements, it's not one itself. It's made by factories.
Have a nice day! :)
To finish calculating the frequency of an electromagnetic wave, you need the wavelength
Chlorine + Calcium --> Ionic Bond
Iron cannot covalently bond as it is a metal
H2(g) + Cl2(g) = 2 HCl(aq) (balanced equation)
1, 1, 2 (coefficients)
