UNIT 4 STRUCTURE OF ATOM & PERIODICTY Flashcards
key concepts / vocab (39 cards)
bohr model
Neils Bohr proposed a model of an atom where the nucleus is the center containing protons and neutrons, and electrons orbit the nucleus in distinct energy levels in spheres- depicting a miniature solar system
atom
smallest unit of an element; consists of a nucleus containing positively charged protons, neutral neutrons, and surrounded by negatively charged electrons orbiting in shells
electrons
negatively charged subatomic particles that orbit the nucleus of an atom
quantum mechanical model
a model of the atom that describes the probability of finding electrons within given orbitals by a three-dimensional model; the probability of finding an electron is calculated by the Schrodinger equation
orbital
the space around an atom’s nucleus where specific pairs of electrons can be found; is characterized by specific shapes and energy levels (s,p,d, or f)
electrons energy level
distinct distances from the nucleus of an atom where electrons may be found; will exist in a ground state energy level, n=0, until it is excited or given energy - then it can move to different energy levels
electrons sublevel
energy levels around the nucleus of an atom that is divided into sublevels or subshell; sublevels within a shell
electrons orbital
three dimensional region around an atom’s nucleus where an electron is most likely to be found
electron shell
specific energy levels surrounding an atom’s nucleus; the outside part of an atom around the atomic nucleus
principal quantum number
(denoted by n), represents the size of an electron orbital and its energy level within an atom
Coulomb’s law
the force of attraction or repulsion between two charged bodies is directly proportional to the product of their charges and inversely proportional to the square of the distance between them; like charges repel, opposite charges attract
electrons electric force
the electrostatic attraction or repulsion between negatively charged electrons
equation for Coulomb’s law
F = k * (q1 * q2) / r²
valence electrons
the electrons int he outermost shell, or energy level, of an atom
core electrons
the inner electrons of an atom that are not considered valence electrons and do not participate in chemical bonding
atomic radius
the distance from the atom’s nucleus to the outer edge of the electron cloud
shielding effect
the phenomenon where inner electrons in an atom block the positive charge of the nucleus from reaching the outer electrons
inner & outer electrons
inner electrons: located in the lowest energy levels closest to the nucleus of an atom
outer electrons: the electrons located in the outermost energy level of an atom
ions
an atom or group of atoms that has an electric charge; ions with positive charge are called cations, ions with negative charge are called anions
ionization energy
the amount of energy needed to remove the valence electrons of an atom
Heisenberg uncertainty principle
states that its impossible to know both the exact position and momentum of a particle simultaneously with perfect accuracy
Schrodinger equation
an equation in quantum mechanics that describes the wave function of an election
quantum numbers
principal quantum number
