Structure of atoms

How was the word atom derived?

It was derived from a geek word a-tomio

What does a-tomio stand for?

Uncuttable and non divisible

Who proposed the first atomic theory

John dalton

What did Michal farady’’s experiment show?

Particulate nature of electricity through which Discovery of electrons took place

Define Cathode ray or cathode ray particle

These are the stream of particles that start flowing from the negative electrode to the positive electrode when high voltage is passed through a cathode tube

What are the results that are inferred from the experiment conducted by Michal faraday?

The cathode rays flow from the cathode to the anode

The cathode rays move in a straight line if they don’t have a magnetic or an electrical field acting upon them

The cathode rays aren’t visible to us but their moments can be observed with the help of materials such as fluorescent and phosphorescent, which can be observed in televisions and pictures

The moment of the cathode rays under a magnetic or electrical field is similar to that of the moment of a negatively charged particle which proves that electrons are present in cathode ray

The properties of an electron are not influenced by the materials used for the electrodes or the type of glass used for making the cathode ray

JJ. Thomson stated that the amount of deviation in the paths of the electrons under the influence of a magnetic or electrical field depends on

Magnitude of the negative charge

Mass of the atom

Strength of the electric or magnetic field

Define Nucleus

Neutrons and protons make up the nucleus

What is the charge of the nucleolus

It is positively charged

How was the discovery of sub atomic partials done?

It was done with the help of electric discharge

What is electric discharge

The process of flow of electric charge

Who called the chadoe ray particles as electrons

JJ thomson

What did RA millikan try to determine

The charge of an electron

What were the different forces that were acting on the Oil droplets in RA Millikan’s experiment

Electrostatic force

gravitational force

Viscous drag force

What observation did RA Millikan make from the experiment he conducted

He observed that the charge acting on the oil droplets were always an integral multiple of the change of an electron

What is the name of the scientist who played a major role in the discovery of protons

Ernest Rutherford

What is the name of the rays that carry positively charged particles?

Canal rays or anode rays

Are anode rays dependent on the nature of the gas present in the tube?

Yes they are

What is the charge to electron ratio of the anode or canal ray dependent on?

The ratio is dependent on the nature of the gas present in the tube

List the inferences made from the excrement performed by ester rutherford

• the properties of the anode rays depend on the nature of the gas in the tube

• The ratio of the charge to the mass of the electron also depends on the nature of the gas filled in the tube

• The properties observed when anode rays are passed through magnetic or electrical frields is the opposite of that of cathode rays

• The mass of the atoms depends on the mature of the gas

Define protons

It refers to the lightest positively charged ion that was obtained from the atom of hydrogen

What was the name of the scientist who discovered neutrons

Chadwick

What charge does an atom contain?

It contains neutral charge

What did thomson’s model resemble or it is also called as

A watermelon or plum or raisin pudding

What was the pro of thomson’s model

It explained the neutrality of an atom

What was the downside of thomson’s model

It didn’t explain the proper distribution of the subatomic particles throughout the atom

What were the observations of Rutherford’s gold foil experiment

• Most of the particles passed through with no change in their path

• Some of the alpha particles were deflected by small angles

• One out of 12000 particles bounced back

What were the inferences made from this gold foil experiment conducted by rutherford

• most of the mass of an atom is densely condensed in one small region of the atom which makes up the nucleus

• The nucleus is surrounded by electrons that move around it at very high speeds in fixed orbits or circular paths

Drawbacks of rutherford’s gold foil model

• It failed to explain the stability of an atom

• It did not specify and elaborate on the electronic structure of an atom

• It did not address the atomic spectrum

• It did not explain the dual nature or character of electromagnetic radiations

Define atomic number, what letter is it denoted by?

The number of protons in an atom (Z)

Define mass number or atomic mass, what letter is it denoted by?

The number of protons and electrons in an atom (A)

Define Isotopes

• They have the same atomic number but different mass number

• They have similar chemical properties but very different physical properties

• Ex- Carbon, hydrogen

Applications of Isotopes

• Isotope of Uranium is used as a fuel in nuclear reactors

• Isotope of cobalt is used in the treatment of cancer

• Isotope of Iodine in the treatment of goiter

Define Isobars

They have the same mass number but different atomic numbers

Ex- Calcium and argon

What are the parameters of a wave?

Wavelength

Amplitude

Period of wave

Wave Number

Frequency of wave

Do electromagnetic waves need a medium to travel in?

No medium is required

Define Black body

It is an ideal body that emits and absorbs all radiations

Define Black body radiation

When a black body emits radiations it is known as black body radiation

State the experimental facts about Black body radiation

• The black body radiation does not depend on the martial of the abject but rather only on the temperature applied on it

• When the temperature applied on the object is increased the black body radiations it emits also increase

• A the temperature applied on the objects increase the height of the graphs decreases

• When you move towards the left of the graph they become smaller

What does Plankton’s Quantum theory state?

It states that atoms or molecules cannot continuously absorb energy but rather it is done in intervals and in discrete amounts

Define quantum

That smallest Quantity of energy absorbed or emitted

What were the results of photoelectric effect?

• As soon as the light was produced on the metal the metal started releasing electrons and the phenomenon of Photoelectricity was observed

• The intensity of the light is directly proportional to the electrons released by the metal

• There is a minimum frequency requirement without which the phenomenon of photoelectricity cannot be observed

• When the frequency of the light is greater than that of the minimum frequency the ions are released with a certain kinetic energy

what are light particles also known as?

They are known as photons

What is the dual nature of electromagnetic radiation?

It behaves as both a wave as well as a particle but in different instances

When does electromagnetic radiation behave as a particle?

It behaves as a particle when it interacts with matter

When does electromagnetic wave behave as a wave

When it propagates

The spectrum from a prism is known as a _____________ spectrum

continuous

Define Emission spectrum

The spectrum of radiation emitted by a substance that has absorbed energy

What is the study of emission and absorption spectrum known as?

Spectroscopy

What did hainsberge state

He stated that the exact position and momentum cannot be determined simultaneously

In the schrodinger equation what does H stand for

Hamiltonian

What are the features of the Quantum Mechanical Model?

• The energy of an electron is quantised

• The orbitals fill up in increasing energy levels

• The orbitals can fit upto only two electrons in them

• The path of the electrons cannot be identified or defined

• The probability of finding an electron is given by the formula of wave frequency square

• The atomic orbital is the wavelength frequency of an atom

___________ helps uf find the path or location of an electron in an atom

Orbitals

_______________ helps us in identifying and finding the shape, size , location, orientation of the orbitals

Quantum numbers

Azimuthal Quantum numbers helps us determine the?

Shape

Magnetic Quantum number helps us determine the?

Orientation

Spin Quantum number helps us determine the?

Spin

Principal quantum number helps us determine the?

size

What are the two different types of nodes?

Radial nodes

Angular nodes

Define Degenerate

Orbitals with the same energy