When an iron rod is heated first it turns to

Cupric chloride produces ………….. colour flame.

Strontium chloride produces……………… colour flame.

…………….. vapours produce yellow light in street lamps.

Elements emit characteristic colours correspond to certain discrete wavelengths of light are called ……………..

Line spectra is formed by …………

The wavelength range of visible spectrum is……….

…………. are used in Radar.

The colour in the sequence VIBGYOR that has least wavelength is ……………

Which electromagnetic waves are sensitive to our eyes?