Atomic Structure Flashcards
Charge magnitude of electrons and protons
1.602x10^-19
Mass of protons and neutrons
1.67x10^-27
Mass of electron
9.11x10^-31
Refers to the number of protons in the nucleus
Atomic Number (Z)
Refers to the sum of the masses of the protons and neutrons
Atomic Mass (A)
Elements that have different number of neutrons
Isotopes
Used to compute atomic mass/weight
Atomic Mass Unit
Corresponds to the weighted average of the atomic masses of the atom’s naturally occurring isotopes
Atomic Weight
Is 1/12 the mass of Carbon 12
1 amu
How many atoms in one mole of a substance?
Avogadro’s Number
Avogadro’s Number
6.022x10^23
A set of principles or laws that govern systems of atomic and subatomic entities
Quantum Mechanics
Model in which electrons are assumed to revolve around the atomic nucleus in discrete orbitals
Bohr Atomic Model
One of its principles stipulates that the energies of electrons are quantized; that is electrons are permitted to have only specific values of energy
Quantum Mechanics
Who designed the Bohr Atomic Model?
Niels Bohr
Represents an early attempt to describe electrons in atoms, in terms of both position and energy
Bohr Atomic Model
Model in which the electron is considered to exhibit both wavelike and particle-like characteristics
Wave-Mechanical Model
Position of an electron in the wave-mechanical model is described by a probability distribution or _____
Electron Cloud
Electrons are in ____ defined by a probability.
orbitals
Each orbital at discrete energy level is determined by ___
Quantum Numbers
Shells are specified by a _____
Principal Quantum Number
The second quantum number signifies the ____
subshell
The number of energy states for each subshell is determined by the third quantum number, ___
ml (magnetic)
Associated with each electron is a ____, which must be oriented either up or down.
Spin Moment
Two possible values for the fourth quantum number
+-1/2
What are the quantum numbers?
n - principal
l - subsidiary
ml - magnetic
ms - spin
Values of energy that are permitted for electrons
Electron States
This principle stipulates that each electron state can hold no more than two electrons, which must have opposite spins
Pauli Exclusion Principle
When all electrons occupy the lowest possible energies in accord with the foregoing restrictions, an atom is said to be in its _______
Ground State
____ or structure of an atom represents the manner in which these states are occupied
Electron Configuration
Are those electrons that occupy the outermost shell
Valence Electrons
Electrons found in unfilled shells
Valence Electrons
States within the outermost or valence electron shell are completely filled
Stable Electron Configurations
Elements that are virtually unreactive chemically
Inert or Noble Gases
Valence electrons determine all of the following properties
Chemical
Electrical
Thermal
Optical
All of the elements have been classified according to electron configuration in the _______
Periodic Table
What are the horizontal rows in the periodic table called?
Periods
What are the Group VIIA elements termed as?
Halogens
What are the Group IA elements termed as?
Alkali
What are the Group IIA elements termed as?
Alkaline Earth Metals
What are the Groups IIIB through IIB elements termed as?
Transition Metals
Term called to elements that are capable of giving up their few valence electrons to become positively charged ions
Electropositive
They readily accept electrons to form negatively charged ions
Electronegative
Which side of the periodic table can you find the electropositive elements?
Left
Which side of the periodic table can you find the electronegative elements?
Right
