Atomic Structure and Periodic Table 1.3.1

Describe how an emission line spectrum is produced

e- in ground state, right amount of energy as heat or electricity, jumps to higher level, excited state is unstable, drops to lower energy level, energy absorbed to make jump released as photon, frequency depends on difference in energy levels. E2-E1 = hf, E2 = excited state, E1 = ground state, h is Planks constant, f is frequency of light

Who unlocked the secret line of spectra?

Bohr

What is an energy level?

Shell which electrons of equal energy can occupy

Which energy level do electrons fall into to produce visible light?

N=2

What is the series of lines called when in n=2?

Balmer series

Give two ways to excite electrons.

High temperature, high voltage electricity

N=1

Gives UV range

N=2

Gives visible range

N=3,4,5

Gives IR range

How is continuous spectrum seen

Incandescent bulb+prism

How is emission line spectrum seen

Excited hydrogen+prism

How is absorption line spectrum seen

Incandescent bulb+cold hydrogen+prism

Continuous spectrum

Contains no bright or dark lines

Absorption spectrum

Interrupted by dark absorption lines

Emission spectrum

Dark except at certain wavelengths where there are emission lines

Sodium

Yellow

Lithium

Crimson

Copper

Blue-green

Strontium

Red

Barium

Green(yellowish)

Flame test

Take wooden splint soaked in deionised water overnight, pick up sample of each salt in turn using fresh splint for each, hold salt into a non-luminous Bunsen flame, now the colours produced

Line absorption spectra

Formed when a white light is passed through a gold gaseous element