ENTRY TEST KEY POINTS & MCQs(CHEMISTRY-11Th ) 1 According to New Syllabus (2024)
charge called positive rays”.
→ J.J Thomson discovered that e/m of positive rays depends on the
→ Protonis 1836 times heavier than electron.
INTRODUCTION:
→ “Atom” means not cutable said by Greek scientists .
→ Plato , Aristotle , Leucippus and Democritus (440 B.C) were most
famous philosophers and scientists of Greek period .
→The Greek scientists thought that all matters are composed of
four elements ,
→ AIR which is hot , cold and wet . → FIRE which is dry and hot . Discovery of Electron (1897)
→ Water which is hot , cold and wet.→ Earth which is dry and cold . → Millikan and J.J Thomson collectively with “oil drop experiment”
→ The theory that atom is smallest (not cutable) particle was calculated charge on electron.
given by John Dalton in 1808.
→ Electrons revolve in orbits & occupy 100,000 times greater
→ Atom take part in chemical reaction.
volume than nucleus and makes 1 % total mass of atom.
→The electrons are attracted by protons and this attractive force
keeps electrons moving around nucleus.
→The mass of electron is 1836 times lighter than Proton and 1839
times lighter than neutron.
→The elements are arranged in periodic table according to
electronic configuration.
→The electrons are also involved in chemical bond formation.
→Inter-Nuclear Part: It is central part of an atom and
contains Protons and Neutrons.
→Extra-Nuclear Part: It is outside part of nucleus of an
atom and contains Electrons revolving in shells.
→Many particles have been discovered within atom include,
1. Proton 2. Electron 3. Neutron 4. Positron 5. Neutrino
Discovery of Neutron (1932)
6. Mesons 7. Hyprons → Neutron was discovered by a famous English physicist
→ Positron is an anti-particle of Electron discovered by a scientist JAMES CHADWICK in 1932.
ANDERSON. → Chadwick bombarded Beryllium with alpha particles.
→Neutrino can be positive ,negative or neutral and discovered → Neutrons must have come out from atoms on dis-
by YUKAWA. integration of bombarded element.
→ Faraday’s experiment indicates the existence of electron. → Chadwick’s equation: 𝟗𝟒𝑩𝒆 + 𝟒𝟐𝑯𝒆 → 𝟏𝟐𝟔𝑪 + 𝟏𝟎𝒏
→ Crook’s tube experiments show the presence of electron and
protons in the atoms.
→ Radioactivity confirms the presence of electron and proton.
→ Chadwick’s experiment shows the presence of neutrons.
→ Spectroscopy reveal the electronic structure of atom.
→ Proton was discovered by Gold Stein 1886.
→ Electron was discovered by J.J Thomson 1897
→Neutron was discovered by James Chadwick 1932.
→ Nucleus was discovered by Rutherford 1911.
→ Electrodes (cathode having negative charge and anode having
positive charge) are metallic plates.
Discovery of Proton (1886)
→ Goldstein said “If thin holes are made in the cathode then some
radiations appear behind the cathode which contains positive
Prepared By: SAIFULLAH BROHI B.S (HON.) & M.Phil (CHEMISTRY)
, ENTRY TEST KEY POINTS & MCQs(CHEMISTRY-11Th ) 2 According to New Syllabus (2024)
Rutherford’s Atomic Theory:
𝑘 1 1
→ The frequency of photon or emitted wave 𝜗 = ( − )
ℎ 𝑛12 𝑛22
→This experiment was given by a New Zealand born British 1 1
→ Wave number of electron in any orbit is ̅𝜗 = 𝑅𝐻 𝑍 2 ( − ).
chemist and Physicist Ernest Rutherford in 1911. 𝑛12 𝑛22
→ He is known as founder of Nuclear Physics.
→He discovered Nucleus of an atom. → 𝑅𝐻 is called Rydberg constant. Its value is 109678 cm-1
→He took a thin gold foil and bombarded with α-particles coming OR 1.096 X 107 cm-1 .
from Polonium atom.
→He observed that most of the alpha particles were passed
straight through the gold foil.
Hydrogen Spectrum:
→ Lyman discovered the series of lines in ultra violet region where
wave length below 4000 A0.
→ Balmer discovered the series of lines in visible .wave length
b/w 4000 to 8000A0
→ Paschen discovered the series of lines in infra red region
→ Bracket discovered the series of lines in mid infra red region.
→ P-Fund discovered the series of lines in Far infra red region.
→ Major portion of the atom is empty.
→ The whole mass of the atom is in the nucleus. RADIOACTIVITY:
→ The Protons are present in the nucleus of atom.
→ The Electrons are present outside the nucleus of atom. →Concept of radioactivity was given by HENRY BEQUEREL in 1896.
→ The Rutherford’s model of an atom is like solar system in which → Emission of invisible radiations from an atom when its nucleus
electrons like planets revolve around nucleus like sun. is broken is called RADIOACTIVITY.
Bohr’s Atomic Theory (1913): → Element which emits these radiations is called radioactive
element.
→ Bohr modified the Rutherford’s mod.
→ Bohr’s theory is based on Quantum theory. →All the elements above Lead (Pb = 82) are naturally
→ The Orbits were called Stationary States by Bohr. radioactive upto atomic number 92.
→ Bohr told stationary states as circular orbits around nucleus.
→ When electron jumps from lower energy level to higher energy → Radioactivity is a nuclear reaction.
level it is said to be in EXCITED STATE.
→ Radium (Ra) is the first radioactive element discovered by
Pierrie Curie and Marie Curie.
238 234 4
→ 92𝑈 → 90𝑇ℎ + 2𝐻𝑒 .
→ Alpha rays are fast moving Helium nuclei.
→Alpha rays consists of two protons and two neutrons .
→ Beta rays are fast moving electrons.
→ Gamma rays are very penetrating.
→ mvr is the angular momentum of electron.→ Only those orbits → Gamma rays are short wave electromagnetic waves.
were possible in which the angular momentum of electron
would be integral multiple of
ℎ QUANTUM THEORY (1900)
2𝜋
→ Quantum theory was given by German physicist Max Planck in
→ Radius of orbit is r = a0 n2 / z here ao = 𝟄0h2/πme2 .
1900 to describe emission and absorption of radiations.
→ The radius for hydrogen atom for first orbit = 0.529 𝐴0
→ Energy can be absorbed or emitted by atoms in small packets
st 2
→ Radius of 1 orbit (n = 1) 𝑟1 = 1 𝑥 0.529 𝐴 = 0 called quanta.
0.529 𝑥 10−8 𝑐𝑚 ( 10−8 𝑐𝑚 = 𝐴0 ).
→ Atoms cannot absorb and emit energy continuously.
nd 2 0 0
→ Radius of 2 orbit (n = 2), 𝑟2 = 2 𝑥 0.529 𝐴 = 2.11 𝐴
→𝐸 = ℎ 𝜗 is the Planck’s equation. Where 𝜗 = 𝑛𝑢 called
2 0
→ Radius of 3rd orbit (n = 3), 𝑟3 = 3 𝑥 0.529 𝐴 = 4.75 𝐴 0 frequency,
→ Energy of an electron in any orbit can be calculated using
1 →h = Plank’s constant = 6.02 𝑥 10−34 J.sec .
equation 𝐸𝑛 = −𝑘( 2 )
𝑛
→ In S.I system 𝐸𝑛 = − 1313 𝐾𝑗/𝑚𝑜𝑙𝑒
Prepared By: SAIFULLAH BROHI B.S (HON.) & M.Phil (CHEMISTRY)
charge called positive rays”.
→ J.J Thomson discovered that e/m of positive rays depends on the
→ Protonis 1836 times heavier than electron.
INTRODUCTION:
→ “Atom” means not cutable said by Greek scientists .
→ Plato , Aristotle , Leucippus and Democritus (440 B.C) were most
famous philosophers and scientists of Greek period .
→The Greek scientists thought that all matters are composed of
four elements ,
→ AIR which is hot , cold and wet . → FIRE which is dry and hot . Discovery of Electron (1897)
→ Water which is hot , cold and wet.→ Earth which is dry and cold . → Millikan and J.J Thomson collectively with “oil drop experiment”
→ The theory that atom is smallest (not cutable) particle was calculated charge on electron.
given by John Dalton in 1808.
→ Electrons revolve in orbits & occupy 100,000 times greater
→ Atom take part in chemical reaction.
volume than nucleus and makes 1 % total mass of atom.
→The electrons are attracted by protons and this attractive force
keeps electrons moving around nucleus.
→The mass of electron is 1836 times lighter than Proton and 1839
times lighter than neutron.
→The elements are arranged in periodic table according to
electronic configuration.
→The electrons are also involved in chemical bond formation.
→Inter-Nuclear Part: It is central part of an atom and
contains Protons and Neutrons.
→Extra-Nuclear Part: It is outside part of nucleus of an
atom and contains Electrons revolving in shells.
→Many particles have been discovered within atom include,
1. Proton 2. Electron 3. Neutron 4. Positron 5. Neutrino
Discovery of Neutron (1932)
6. Mesons 7. Hyprons → Neutron was discovered by a famous English physicist
→ Positron is an anti-particle of Electron discovered by a scientist JAMES CHADWICK in 1932.
ANDERSON. → Chadwick bombarded Beryllium with alpha particles.
→Neutrino can be positive ,negative or neutral and discovered → Neutrons must have come out from atoms on dis-
by YUKAWA. integration of bombarded element.
→ Faraday’s experiment indicates the existence of electron. → Chadwick’s equation: 𝟗𝟒𝑩𝒆 + 𝟒𝟐𝑯𝒆 → 𝟏𝟐𝟔𝑪 + 𝟏𝟎𝒏
→ Crook’s tube experiments show the presence of electron and
protons in the atoms.
→ Radioactivity confirms the presence of electron and proton.
→ Chadwick’s experiment shows the presence of neutrons.
→ Spectroscopy reveal the electronic structure of atom.
→ Proton was discovered by Gold Stein 1886.
→ Electron was discovered by J.J Thomson 1897
→Neutron was discovered by James Chadwick 1932.
→ Nucleus was discovered by Rutherford 1911.
→ Electrodes (cathode having negative charge and anode having
positive charge) are metallic plates.
Discovery of Proton (1886)
→ Goldstein said “If thin holes are made in the cathode then some
radiations appear behind the cathode which contains positive
Prepared By: SAIFULLAH BROHI B.S (HON.) & M.Phil (CHEMISTRY)
, ENTRY TEST KEY POINTS & MCQs(CHEMISTRY-11Th ) 2 According to New Syllabus (2024)
Rutherford’s Atomic Theory:
𝑘 1 1
→ The frequency of photon or emitted wave 𝜗 = ( − )
ℎ 𝑛12 𝑛22
→This experiment was given by a New Zealand born British 1 1
→ Wave number of electron in any orbit is ̅𝜗 = 𝑅𝐻 𝑍 2 ( − ).
chemist and Physicist Ernest Rutherford in 1911. 𝑛12 𝑛22
→ He is known as founder of Nuclear Physics.
→He discovered Nucleus of an atom. → 𝑅𝐻 is called Rydberg constant. Its value is 109678 cm-1
→He took a thin gold foil and bombarded with α-particles coming OR 1.096 X 107 cm-1 .
from Polonium atom.
→He observed that most of the alpha particles were passed
straight through the gold foil.
Hydrogen Spectrum:
→ Lyman discovered the series of lines in ultra violet region where
wave length below 4000 A0.
→ Balmer discovered the series of lines in visible .wave length
b/w 4000 to 8000A0
→ Paschen discovered the series of lines in infra red region
→ Bracket discovered the series of lines in mid infra red region.
→ P-Fund discovered the series of lines in Far infra red region.
→ Major portion of the atom is empty.
→ The whole mass of the atom is in the nucleus. RADIOACTIVITY:
→ The Protons are present in the nucleus of atom.
→ The Electrons are present outside the nucleus of atom. →Concept of radioactivity was given by HENRY BEQUEREL in 1896.
→ The Rutherford’s model of an atom is like solar system in which → Emission of invisible radiations from an atom when its nucleus
electrons like planets revolve around nucleus like sun. is broken is called RADIOACTIVITY.
Bohr’s Atomic Theory (1913): → Element which emits these radiations is called radioactive
element.
→ Bohr modified the Rutherford’s mod.
→ Bohr’s theory is based on Quantum theory. →All the elements above Lead (Pb = 82) are naturally
→ The Orbits were called Stationary States by Bohr. radioactive upto atomic number 92.
→ Bohr told stationary states as circular orbits around nucleus.
→ When electron jumps from lower energy level to higher energy → Radioactivity is a nuclear reaction.
level it is said to be in EXCITED STATE.
→ Radium (Ra) is the first radioactive element discovered by
Pierrie Curie and Marie Curie.
238 234 4
→ 92𝑈 → 90𝑇ℎ + 2𝐻𝑒 .
→ Alpha rays are fast moving Helium nuclei.
→Alpha rays consists of two protons and two neutrons .
→ Beta rays are fast moving electrons.
→ Gamma rays are very penetrating.
→ mvr is the angular momentum of electron.→ Only those orbits → Gamma rays are short wave electromagnetic waves.
were possible in which the angular momentum of electron
would be integral multiple of
ℎ QUANTUM THEORY (1900)
2𝜋
→ Quantum theory was given by German physicist Max Planck in
→ Radius of orbit is r = a0 n2 / z here ao = 𝟄0h2/πme2 .
1900 to describe emission and absorption of radiations.
→ The radius for hydrogen atom for first orbit = 0.529 𝐴0
→ Energy can be absorbed or emitted by atoms in small packets
st 2
→ Radius of 1 orbit (n = 1) 𝑟1 = 1 𝑥 0.529 𝐴 = 0 called quanta.
0.529 𝑥 10−8 𝑐𝑚 ( 10−8 𝑐𝑚 = 𝐴0 ).
→ Atoms cannot absorb and emit energy continuously.
nd 2 0 0
→ Radius of 2 orbit (n = 2), 𝑟2 = 2 𝑥 0.529 𝐴 = 2.11 𝐴
→𝐸 = ℎ 𝜗 is the Planck’s equation. Where 𝜗 = 𝑛𝑢 called
2 0
→ Radius of 3rd orbit (n = 3), 𝑟3 = 3 𝑥 0.529 𝐴 = 4.75 𝐴 0 frequency,
→ Energy of an electron in any orbit can be calculated using
1 →h = Plank’s constant = 6.02 𝑥 10−34 J.sec .
equation 𝐸𝑛 = −𝑘( 2 )
𝑛
→ In S.I system 𝐸𝑛 = − 1313 𝐾𝑗/𝑚𝑜𝑙𝑒
Prepared By: SAIFULLAH BROHI B.S (HON.) & M.Phil (CHEMISTRY)
