Structure of Atom (INCOMPLETE)

JEE and IISER stuff

What are the main postulates of John Dalton’s Atomic Theory?

1. All matter was composed of a small particle called an atom.

2. Atom is the smallest indivisible part of matter which takes part in chemical reaction.

3. Atoms can neither be created nor destroyed.

4. Atoms of the same element are similar in size, mass and characteristics; however atoms of different elements have different size, mass and characteristics.

Atomic radii are of the order ___.

10^-8 cm = 10^-10 m

Electrons were discovered by which method and by whom?

Electrons were discovered as a result of a study of cathode rays by JJ Thompson.

What is a the charge on an electron?

1.6 × 10^-19 C

What is the mass of a single electron?

9.11 × 10^-31 kg

What is the mass of one mole of electrons?

0.55 mg

Whom was the name “electron” given by?

Stony.

What is a cathode ray discharge tube?

A cathode ray tube is a partially evacuated tube, made of glass, containing two thin pieces of metal, called electrodes, sealed in it.

Describe cathode rays.

When sufficiently high voltage (around 10000 volts or more) is applied across the electrodes, current starts flowing through a stream of particles moving in the tube from the negative electrode (cathode) to the positive electrode (anode). These were called cathode rays or cathode ray particles, as they are emitted from the negative electrode (cathode).