Atomic Structures Flashcards
What has a positive charge and mass around 1 amu
Proton
What has no charge and mass around 1 amu
Neutron
What has a negative charge and negligible mass
Electron
The nucleus contains what subatomic particals
Protons and neutrons
Where are the electrons of an atom located
Orbiting around the nucleus
The number of protons in a given element is called what
Atomic number
The sum of an element’s protons and neutrons is called what
Mass number
What is the sum of an element’s protons and neutrons called
Atomic mass
The mass number and atomic mass are related how
They are the same
What are atoms of a given element that have a difference in the number of neutrons called
Isotopes
The three isotopes of hydrogen
Protium, deuterium, and tritium
The weighted average of the naturally occurring isotopes of an element is called
Atomic weight
Rutherford first postulated what
Atom had a dense, positively charged nucleus that made up only a small fraction of the volume of the atom
A dense, positively charged nucleus is surrounded by electrons revolving around the nucleus in orbits with distinct energy levels in what model
Bohr model of the atom
The energy difference between energy levels is called a
Quantum
Quantization means what
there is not an infinite range of energy levels available to an electron; electrons can exist only at certain energy levels
Where does an electron have the highest energy levels
When it is far away from the nucleus
The ______ of an element is unique; for an electron to jump from a lower energy level to a higher one, it must absorb an amount of energy precisely equal to the energy difference between the two levels
atomic absorption spectrum
When electrons return from the excited state to the ground state, they emit an amount of energy that is exactly equal to the energy difference between the two levels; every element has a characteristic ____________, and sometimes the electromagnetic energy emitted corresponds to a frequency in the visible light range
atomic emission spectrum
Electrons do not travel in defined orbits but rather are localized in orbitals, which is what model
Quantum mechanical model
What principle states that it is impossible to know both an electron’s position and its momentum exactly at the same time
Heisenberg uncertainty principal
How many quantum numbers are there
4
What describes the average energy of a shell
Principal quantum number, n
What describes the subshells within a given principal energy level
Azimuthal quantum number, L
