Karteikarten
Atomic Structure
Karten in diesem Stapel (49)
- 1atombasic building block of matter, representing the smallest unit of a chemical structure
- 2subatomic particles1. proton
2. neutron
3. electron - 3nucleuscore of the atom
- 4elementcomposed of atoms alike in size, mass, and chemical properties
- 5Dalton's Atomic Theorytheorized in the early 1800s by English scientist John Dalton, formulated theory of invisible building blocks of matter which came to be known as atoms
- 6compoundcomposed of atoms of more than one element
- 7chemical reactioninvolves the separation, combination, or rearrangement of atoms, however NOT the creation or destruction of such
- 8(amu)unified atomic mass unit, which is equivalent to one Dalton (Da)
- 9atomic number (Z)equivalent to number of protons found in an atom of that element
- 10protonsubatomic particle contained in the nucleus possessing a single charge in its mass of 1 amu
determines atomic number of an element - 11neutrona subatomic particle contained in the nucleus contributing 1 amu, yet no charge
- 12electronsubatomic particle contained in orbital shells contributing a single negative charge with negligible mass
- 13iona positively or negatively charged atom
- 14mass number (A)equal to total number of nucleons contained within in the atom
- 15nucleoncorresponds to subatomic particles contained within the nucleus, namely protons and neutrons
- 16molecular weightweight in grams per one mole of a given element
- 17moleunit used to count particles, represented by Avogadro's number which is equivalent to 6.02 * 10^23
- 18isotopesspecies which possess the same number of protons but a different number of neutrons, resulting in different masses
- 19standard atomic weightweighted average of all isotopes of an element found naturally on Earth
- 20Ernest Rutherforddemonstrated in 1911 than an atom has a dense, positively charged nucleus that accounts for only a small portion of the volume of an atom
- 21Max Planckdeveloped the first quantum theory in 1900, proposing that energy emitted as electromagnetic radiation from matter comes in discrete bundles called quanta
- 22energy value of a quantumE=hf
- 23Planck's constantdesignated as h
value is equivalent to 6.626 * 10^-34 J-s - 24angular momentum of an electron (equation)L = nh / 2π
- 25energy of an electron (equation)E = -Ry / n^2
- 26Rhydberg energy2.18 * 10^-18 J/e-
- 27relationship between energy and orbital radiussmaller the radius, the lower the energy state of the electron
- 28ground statelowest energy state of an electron (n=1)
- 29electromagnetic energy of photons (equation)E = hc / λ
- 30line spectrumquantized energies of light emitted under excited conditions
each line on an emission spectrum corresponds to a specific electronic transition - 31atomic emission spectraeach element's unique excitation energy level
- 32energy change between differing energy states (equation)E = hc / λ = -Ry (1/n2i - 1/n2f)
- 33absorption spectraused in the identification of elements present in a gas sample by measuring the wavelengths of emission and relating the conclusions to wavelengths of absorption
- 34orbitalrepresentation of the probability of finding an electron within a given region in the space surrounding the nucleus
- 35Heisenberg Uncertainty Principlestates that it is impossible to simultaneously determine with perfect accuracy the momentum and position of an electron
- 36quantum numbersdescribes the position and energy of an electron
denoted by: n, l, ml, ms - 37Pauli Exclusion Principlestates that no two electrons in a given atom can possess the same set of four quantum numbers
- 38principal quantum numberdenoted by "n," represents the electron shell
maximum "n" occurs at the ground state, which corresponds to element period (row)
maximum number of electrons in shell = 2n^2 - 39Azimuthal quantum numberdenoted by "l," describes angular momentum and shape of electron orbital
l = n - 1, maximum electrons = 4l + 2
greater l = greater energy
0 = S, 1 = p, 2 = d, 3 = f - 40magnetic quantum numberdesignated as ml, describes the orientation in space of the electron shell
possible values: -l through +l, including 0 - 41spin quantum numberdenoted by ms, describes spin (intrinsic angular momentum)
only two possibilities: ±1/2 - 42paired electronselectrons with opposite spins in the same orbital
- 43parallel electronselectrons in different orbitals with the same spin
- 44electron configurationdescribes patter by which subshells are filled and the number of electrons within each principal level and subshell
- 45Aufbau Principlestates that subshells must be filled from lowest to highest energy, each subshell will fill completely before electrons enter the next one
- 46Hund's Rulestates that within a given subshell, orbitals are filled such that there are a maximum number of 1/2 filled orbitals with parallel spins
- 47paramagneticdescribes a material with unpaired electrons which will be aligned in the presence of a magnetic field
slight magnetic attraction - 48diamagneticdescribes a material with no unpaired electrons, which will be slightly repelled by a magnetic field
- 49valence electronsthe electrons which occupy the outermost energy shells and or are available for chemical bonding