atomic structure and the periodic table. basics of periodic table each box on the table represents...
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Isotope symbol (neutral) Mass number (#p + #n) Atomic number (#P) Isotope nameTRANSCRIPT
Atomic Structureand thePeriodic Table
Basics of Periodic Table Each box on the table represents an
element. In each box…
an element symbol the element’s atomic number the element’s average atomic mass
Elements arranged in order of increasing atomic number.
Isotope symbol (neutral)Mass number(#p + #n)
Atomic number(#P)
Isotope name
C146
Isotope symbol (charged)
23416S
Average Atomic Mass The masses found on the periodic
table are called average atomic masses.
They represent the weighted average of all the isotopes found in a sample of the element Isotopes are atoms of the same element
with different numbers of neutrons
ExampleThe atomic masses of the two stable isotopes of
boron, boron-10 (19.78%) and boron-11 (80.22 %), are 10.0129 amu and 11.0093 amu, respectively. Calculate the average atomic mass of boron.
Remember… Electron configuration…ie. Shorthand
Should be able to do shorthand w/o diagonal rule Aufbau principle – electrons fill energy levels
and sublevels in order of increasing energy Pauli Exclusion principle – no two electrons can
have the same set of four quantum numbers (which means no two electrons can be in the same place at the same time
Hund’s rule – when adding electrons to sublevels with more than one orbital, each orbital gets its own electron first before pairing
s orbitals
p orbitals
d orbitals
f orbitals
Quantum Numbers Just as a point on an xy-graph needs a
set of two coordinates, each electron has a unique set of four coordinates.
These four coordinates represent shell (energy level), subshell (sublevel), orbital, and spin direction of the electron.
Principal Quantum number
Represented by n Corresponds to the rows of the
periodic table Therefore n = 1, 2, 3, and so on Tells the size of the electron cloud
2nd Quantum number Represented by l Called the angular momentum quantum
number Describes the shape of the orbital l can have the values from 0 to n-1
0 = s sublevel 1 = p sublevel 2 = d sublevel 3 = f sublevel
3rd Quantum Number Called the magnetic quantum number Describes the orientation in space of the orbital
Whether the path of the electron lies on the x, y, or z axis
Represented by ml
ml can have values from –l to +l if l = 2, then ml = -2, -1, 0, +1, +2
4th Quantum Number Corresponds to the spin of an
electron Represented by ms
Clockwise represented by +1/2 Counterclockwise represented by -
1/2
Therefore Mg (3, 0, 0, -1/2)
Bi (6, 1, +1, +1/2)
Co (3, 2, -1, -1/2)
Cf (5, 3, -1, -1/2)
Diamagnetism/Paramagnetism Diamagnetic elements have all of
their electrons spin paired. Which means they have complete
sublevels. Are not affected by a magnetic field
Paramagnetic elements do not have all of their electrons spin paired. Strongly affected by a magnetic field
Ground State vs Excited State In a ground state atom, all electrons are
in the lowest available sublevels.
For an atom in the excited state, one or more electrons have absorbed enough energy to jump to higher energy levels. As soon as possible, those excited electrons
will release the energy in the form of a photon, possibly as colored light.
Shorthand for ionsCa2+ 1s22s22p63s23p6
K+ 1s22s22p63s23p6
Cl- 1s22s22p63s23p6
S2- 1s22s22p63s23p6
P3- 1s22s22p63s23p6
All of these ions have the same configuration as argon and are isoelectronic.