UNIT 2 - Atomic Structure Flashcards
State the Hund’s rule of maximum multiplicity.
When filling degenerated orbitals electron fill all the orbitals singly before occupying them in pairs.
State the most known contribution to the discovery of atomic structure made by E Rutherford.
gold foil experiment - firing alpha particles at a piece of gold foil
discovery of nucleus
What does degenerated mean?
With equal energy.
List the 2 exceptions in the electron configuration.
Cr:[Ar] 4s1 3d5
Cu:[Ar] 4s1 3d10
Define the terms cation and anion.
cation - atom that lost electrons
anion - atom that gained electrons
changes in chemical properties
State the Aufbau principle.
Means “building up” in German.
The electrons fill the lowest energy orbital that is available first.
What does the statement “the energy of the atom is quantized” mean?
The electron cannot change its energy in a continuous way only by discrete amounts.
Define valence electrons.
Positioned on the outer energy level.
Are mainly responsible for compound formation.
Define the mass spectrometer.
Instrument enabling the measurement of the mass of individual atoms but we give relative atomic mass.
List the components of an electromagnetic spectrum.
“Rabits mate in very unusual expensive garden”
- radio waves
- microwaves
- infrared radiation
- visible light (ROYGBIV)
- ultrared radiation
- x-rays
- gamma rays
Distinguish absorption spectrum emission spectrum.
absorption - shows the radiation absorbed as atoms move from a lower to a higher energy level
emission - produced when an atom moves from a higher energy level to a lower one
Define the term isotopes.
Atoms of the same element with different mass numbers, same chemical properties, different physical properties.
State the most known contribution to the discovery of atomic structure made by Niels Bohr.
Positively charged nucleus and electrons travelling on orbits basically what we have today.
Define the term electromagnetic radiation.
Energy the electron gives out when it falls down lower levels.
One packet of energy (quantum/photon) is released for each electron transition, the energy is proportional to the frequency of the radiation.
State the Heisenberg’s Uncertainty Principle.
It is impossible to know where exactly an electron is at any given moment in time.
Define the term first ionization energy.
Energy required to remove an electron from a neutral atom in gaseous state.
State the most known contribution to the discovery of atomic structure made by JJ Thomson.
Plum pudding model of an atom (negative charged particles swim in positively charged sea) discovered electrons.
State the relation between frequency and wavelength.
The shorter the wavelength the higher the frequency.
Distinguish mass number from atomic number.
Mass number (A) describes the number of nucleons in an atom
Atomic number (Z) describes number of protons
Define the term excited state.
unstable state of an electron that moved into an orbit or higher energy level when the atom absorbed energy.
Usually swiftly followed by a fall back to GROUND STATE.
Name the atomic transitions of hydrogen.
Lyman series (to ground state).
Balmer series (to n=2)
Paschen series (to n=3)
What is a paradigm shift?
Major change in the worldview, concepts and practices of how something works/ is accomplished.
Explain why as the size of the atomic radius increases the IE decreases.
There are more shells so the force required to remove the electron is significantly lower as the attraction of the nucleus is lower as well.
State the Pauli exclusion principle.
Any orbital can hold max of 2 electrons and these electrons must have opposite spins,
in an atom we cannot have 2 electrons with equal values of all quantum numbers so they must have at least different spin.
Define the term wavelength.
Distance over which the shape of the wave repeats.
Distance between two successive crests or throughs.
State the most known contribution to the discovery of atomic structure made by John Dalton.
Matter is made of small particles.
Defined atoms and compounds and that they cannot be neither created nor destroyed.
Define the term element.
Substance that cannot be broken down into simpler substances in a chemical reaction
“atom” is derived from Greek “not able to be cut”.
How can physical properties be measured?
Without changing the chemical composition of a substance.
List the sub-atomic particles.
Nucleus: protons + electrons = nucleons
electrons
Define the term compound.
Substance made by chemically combining two or more elements.
Has different properties from its constituent elements.
Associate the emission spectrum of hydrogen with its regions of the electromagnetic spectrum.
Lyman = UV
Balmer = Visible
Paschen = Infrared
Define the term frequency.
Number of waves that pass a particular point in 1s.
