Atomic structure

Question 1

Define Subatomic particles

Answer 1

a subatomic particle is a particle that is smaller than an atom.

Question 2

Define Cathode ray

Answer 2

the stream of negatively charged particles called electrons

Question 3

list the properties of Cathode rays

Answer 3

. they travel in straight line and produce sharp shadows
.when cathode ray strikes a solid target of high atomic weight, it produces x rays
. cathode ray has velocity up to 1/10th of velocity of light
.Cathode ray exerts mechanical pressure

Question 4

Define anode rays

Answer 4

the stream of positively charged protons

Question 5

list the properties of anode rays

Answer 5

. they have heating affect
.they are also deflected by magnetic field
.they cast shadow of object in their path
. they travel in straight line opposite to that of cathode rays

Question 6

what are the postulates of rutherford’s atomic model

Answer 6

. it couldnt explain the stability of atoms-> charged particles such as electrons should lose energy and gradually fall into the nucleus and should collapse into the nucleus. but it isnt explained in rutherford’s model

.it couldnt explain the origin of line of spectra of atoms -> atoms such as hydrogens emit light spectra which are discrete, but rutherford says that the electron revolving around the nucleus produces continuous energy spectrum.

Question 7

list the postulates of dalton’s atomic theory

Answer 7

.every matter is made of atoms
.atoms are indivisible
.atoms can neither be created nor destroyed
.atoms of different elements vary
.atoms of dame element are identical