Finals Chapter 5-6 Flashcards
electromagnetic radiation
a form of energy that exhibits wavelike characteristics as it travels through space
Amplitude
a waves height from the origin to crest or trough
wavelength
shortest distance between equivalent points on a continuos wave
frequency
number of waves that pass through a given point per second
electromagnetic spectrum
encompasses all forms of electromagnetic radiation, with the only differences in the types of radiation being their frequencies and wavelengths
quantum
the minimum amount of energy that can be gained or lost by an atom
Planck’s constant
6.626x10^-34 J*s
photoelectric effect
when electrons, called photoelectrons, are emitted from a metals surface when light of a certain frequency shines on the surface
photom
a particle of electromagnetic radiation with no mass that carries a quantum of energy
atomic emission spectrum
set of frequencies of the electromagnetic waves emitted by atoms of the element
ground state
lowest allowable energy state of an atom
de Broglie equation
predicts that all moving particles have wave characteristics
Heisenberg uncertainty principle
it is fundamentally impossible to know precisely both the velocity and position of a particle at the same time
quantum mechanical model of the atom
the atomic model in which electrons are treated as waves
atomic orbital
a three-dimensional region around the nucleus
principle quantum numbers(n)
indicate the relative sizes and energies of atomic orbitals
principal energy levels
the atoms major energy levels
energy sublevels
contained in principle energy levels ( s, p, d, f)
electron configuration
the arrangement of electrons in an atom
Aufbau principle
each electron occupies the lowest energy orbital available
Pauli exclusion principle
states that a maximum of two electrons may occupy a single atomic orbital, but only if the electrons have opposite spins
Hund’s rule
states that single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals
valence electrons
are defined as electrons in the atoms outmost orbitals
electron-dot structure
elements symbol surrounded by dots representing the atoms valence electrons
who was John Newlands
an english chemist who proposed that the elements made a periodic pattern which he called octaves
what did Mendeleev notice when the elements were ordered by increasing atomic mass?
there was a repetition
who organized the elements into the first periodic table?
Mendeleev
Moseley’s periodic law states:
there is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number
columns of periodic table
groups
rows of periodic table
periods
representative elements
the groups designated with an A (1A through 8A) also referred to as main group because they possess a wide range of chemical and physical properties
transition elements
the groups designated with a B ( 1B through 8B)
metals
elements that are generally shiny when smooth and clean and solid at room temperature
alkali metals
group 1A elements (except hydrogen)
alkaline earth metals
Group 2A elements
Group B elements or _____ elements, are divided into _____ _____ and _____ ______ _______
transitions, transition metals, inner transition metals (lanthanide and actinide series)
phosphors
substances that emit light when struck by electrons
nonmetals
elements that are generally gasses or brittle dull looking solids
halogens
group 7A elements. Highly reactive
noble gasses
group 8A elements. Extremely unreactive
Metalloids
elements with physical and chemical properties of both metals and non-metals
atoms in the same group have similar chemical properties, because:
they have the same number of valence electrons
