Chemistry - Atomic Structure (Ch 1 formulas)
shape of d orbital
four-leaf clover
last line has max ____ and min ____
frequency, wavelength
third line of any series
gamma series
phosphorescent
giving off light without heat
greater the value of principal quantum number
greater is the distance of nucleus and energy of the shell
final kinetic energy
initial potential energy
Drawbacks of Rutherford's Model
it could not explain the stability of an atom. if electrons lose energy continuously the spectrum would be continuous but it consists of well defined lines of definite frequencies.
Heisenberg uncertainty principle
it is impossible to know exactly both the velocity and the position of a particle at the same time
charge is quantised
minimum amount of chaege a body can have is +/- 1.6*10^-19 C .
seperation energy
minimum energy needed to move an atom from its excited state
isosters
molecules with same number of atoms and electrons
second postulate on which Bohr's atomic model is based on
negatively charged electron revolve around the nucleus in the same way the planets revolve around the sun. the path of electron is circular. the attraction force between nucleus and electron is equal to the centrifugal force on electron.
frequency of wave
number of complete waves that pass a point per second
smallest packet of energy of light
photon
if the value of n is same then the oder of energy of the various subshells will be
s<p<d<f (only for multi electron species)
isotones/isoneutronic species/isotonic
same number of neutrons, different number of protons
isobars don't have
same physical and chemical property
isotopes do not have
same value of e/m
bohr model is applicable only for
single electron species
total energy transmitted from one body to another will be
some integral multiple of energy of a quantum
quantum numbers
specify the properties of atomic orbitals and the properties of electrons in orbitals
frequency equals
speed of light/wavelength
shape of s orbital
sphere
magnetic quantum number (m)
symbolized by m, indicates the orientation of an orbital around the nucleus
principal quantum number (n)
symbolized by n, indicates the main energy level occupied by the electron
radius of the nucleus is proportional to
the cube root of the number of nucleons within it.
Hydrogen Line Spectrum
the em spectrum of hydrogen.
sixth postulate on which Bohr's atomic model is based on
the emission or absorption of energy in the photon can only occur when electron jumps from one stationery state to another. energy is absorbed when electron jumps from inner to outer orbit and is emitted when electron moves from out to inner orbit.
excitation energy
the energy required to move an electron from a lower energy level to a higher energy level
Ionisation energy
the energy required to remove an electron from an atom
Amplitude
the height of a wave's crest
bohr's theory and de-broglie concept
the nature of an electron moving around the nucleus is like a wave that flows in circular obits around the nucleus. if an electron is regarded as a wave, the quantum condition as given by Bohr in his theory is readily fulfilled.
Atomic number of an element (Z)
the number of protons in each atom of the element
fourth postulate on which Bohr's atomic model is based on
the orbits in which electron can revolve are known as stationary orbits because in these orbits energy of electron is always consistent.
electromagnetic spectrum
the range of wavelengths or frequencies over which electromagnetic radiation extends.
mass number (A)
the total number of protons and neutrons in the nucleus of an atom
Properties of cathode rays
they move in a straight line particles of cathode ray have mass particles are made of -ve particles amount of deflection is proportional to charge/mass charge/mass ratio remains constant.
first line has max _____ and min ____
wavelength, frequency
radial nodes
}|+ +
charge of a electron
-1.6 x 10^-19 C
final potential energy
0
initial kinetic energy
0
value of l lies between
0 to n-1 in a particular shell
Dalton's Atomic Theory
1) elements are composed of atoms. 2) atoms of same element are identical, but differ from other elements. 3) elements can mix together 4) atoms only change when mixed with other elements
Charge of a proton
1.6 x 10^-19 C
e/m value constant
1.7*10^11 C/Kg
kinetic energy
1/2 mv^2
time period of wave
1/frequency
if value of l is same but value of n is different then the order of energy will be
1s<2s<3s<4s<5s<6s, 3d<4d<5d<6d, 4p<5p<6p
radius of an atom
1x10^-10m
radius of nucleus
1x10^-15
the number of electrons in a particular subshell is equal to
2(2l +1)
charge of alpha particle
3.2 * 10^-19 C
Distance of closest approach
4ZKe^2/mv^2
Planck's constant (h)
6.626 x 10^-34
orbital
A 3D region around the nucleus that indicates the probable location of an electron.
electromagnetic waves
A form of energy that can move through the vacuum of space.
Lyman series
A set of spectral lines that appear in the UV region when a hydrogen atom undergoes a transition from energy levels n>1 to n=1.
Balmer series
A set of spectral lines that appear in the visible light region when a hydrogen atom undergoes a transition from energy levels n>2 to n=2.
Paschen series
Set of spectral lines resulting when a hydrogen atom undergoes a transition from energy levels n>3 to n=3.
Brackett Series
Set of spectral lines resulting when a hydrogen atom undergoes a transition from energy levels n>4 to n=4.
Pfund Series
Set of spectral lines resulting when a hydrogen atom undergoes a transition from energy levels n>5 to n=5.
humphrey series
Set of spectral lines resulting when a hydrogen atom undergoes a transition from energy levels n>6 to n=6.
isoelectric species
atoms and ions that have the same number of electrons in their outer shell
first postulate on which Bohr's atomic model is based on
atoms has a nucleus where all protons and neutrons are present. the size of nucleus is very small and it is present at the centre of the atom.
wave number
The number of waves per centimeter.
spin quantum number (s)
The quantum number that has only two possible values, +1/2 and -1/2, which indicate the two fundamental spin states of an electron in an orbital
isodiaphers
atoms of different element which have same difference of the number between neutrons and protons
isobars
atoms of different elements with same mass number but different atomic number.
second line of any series
beta series
Values of a principal quantum number?
between 1 and infinity
shape of f orbital
complex
wave mechanical model of atom
consists of de-Broglie concept and Heisenberg's Uncertainty Principle
Millikan's Oil Drop Experiment
determined the charge of the electron in an oil drop
energy of each quantum is
directly proportional to the frequency of the radiation
shape of p orbital
dumbbell
fifth postulate on which Bohr's atomic model is based on
each stationary orbit is associated with definite amount of energy therefore these orbits are also called energy levels
mass of _____ is less than that of hydrogen.
electron
third postulate on which Bohr's atomic model is based on
electrons can revolve only in these orbits in which angular momentum of electron is integral multiple of h/2pi.
classification of spectrum
emission spectrum and absorption spectrum
Planck's Quantum Theory
energy emitted as electromagnetic radiation from matter exists in discrete bundles called quanta
cathode tube experiment
experiment done by JJ Thomson in which he discovered the electron
azimuthal quantum number (l)
Second quantum number, designated l. Tells us the shapes of the electron orbitals
Bohr's Atomic Model
Atoms have levels surrounding the nucleus where electrons are found. Levels can hold different amounts of electrons depending on their distance from the nucleus.
isotopes
Atoms of the same element that have different numbers of neutrons
atomic weight
Average of the mass numbers of all isotopes
Coloumb's Law
F=kq1q2/r^2
Wavelength
Horizontal distance between the crests or between the troughs of two adjacent waves (lambda)
Neutrons were discovered by
James Chadwick in 1932
initial potential energy
K(2e)(Ze)/r
potential energy of charge q1 due to charge q2
Kq1q2/r
JJ Thomson's atomic model
Plum pudding model
when an electric excitation is applied on hydrogen atomic gas at low pressure,
a bluish light is emitted. when it is passed through prism, a spectrum of several isolated sharp lines is obtained.
node
a point, line, surface or plane in which probability of finding an electron is maximum
the dual nature of matter
according to de-Broglie, if the nature of light is both that of a particle of a wave, then this dual behaviour should be true also for the matter
value of magnetic quantum number
all integral value from -l to l including 0
first line of any series
alpha series
