Discovery Of Electron

Question 1

Method Of Discovery

Answer 1

• Discovered in discharge tube experiment
• Discharge tube has gas at very low pressure
• When large potential difference applied cathode rays formed

Question 2

Properties of Cathode Rays

Answer 2

1) Generated at cathode and move towards anode
2) Produce fluorescence upon attacking ZnS screen
3) Travel in straight lines (in absence of electric or magnetic field)
4) Behave like negatively charged particles i.e. move towards +ve plate (anode) (in presence of electric or magnetic field). Called electrons
5) Cathode Ray characteristics independent of nature of gas and material of electrodes
6) Can rotate a wheel, hence not massless

Question 3

Charge

Answer 3

-1.602 X 10^-19 C`

Question 4

Charge to Mass ratio

Answer 4

1.758 X 10^11 C/kg

Question 5

Relative Charge

Answer 5

-1

Question 6

Mass

Answer 6

9.1 X 10^-31 kg