1. Electromagnetic Spectrum
Bohr’s Model of the Atom

2. Electromagnetic Spectrum: different types of energy that travel in waves
the wave pattern is made of electric and magnetic fields that can travel through empty space
ex: UV rays, microwaves, visible light
type of energy depends on frequency & wavelength

3. wavelength = distance between 2 crests or 2 troughs
frequency = how often a wave repeats itself in 1s represented by , measured in Hz
wavelength = distance between 2 crests or 2 troughs
represented by  (Greek symbol lamda), measured in meters
wavelength of visible light is usually measured in nanometers (nm) = 10-9 m

4. How are  and  related?
the shorter the , the higher the  (the more  the wave contains)
the longer the , the lower the  (the less  the wave carries)
longer  are safe for humans, short  can be harmful
this is why radio waves are safe but X-rays are not

6. Visible Light
High Energy
Low Energy

7. ex: white light, which is real light that we see
continuous spectrum : a spectrum in which all the wavelengths of light are represented in an uninterrupted sequence
ex: white light, which is real light that we see
it’s a bunch of colours smeared together

8. line spectrum = distinct colour lines rather than white light, unique to each element
aka discontinuous spectrum
each of the bands represents one jump of an electron

9. Why?? each element gives off their own distinct bands of colour
the bands appear in the sections that correspond to various elements
Hydrogen
Carbon

10. The Bohr Model of the Atom
Electrons travel in orbits
Orbits are at fixed distances
Electrons will continue on their path until told to do otherwise. (Energy)

11. Elements and their Colours
e– can become excited and can “jump” to a higher shell
when the E is removed, the excited e– “falls” back down to its ground state and releases its E in the form of light

12. spectroscope = instrument that separates light into its component bands of colour
uses a prism or a diffraction grating
we use them to identify elements contained in a substance (ex: stars)
we can also tell if a body in space is moving towards us or moving away