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electromagnetic radiation

answer

one of the ways that energy travels through space Gamma, X-Rays, UV, Visible, IR, Micro,Radio (FM, short, AM)

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wavelength

answer

-distance between two consecutive peaks or troughs in a wave -measured in meters

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frequency

answer

-number of waves that pass a given point per second -measured in hertz (sec⁻¹)

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speed

answer

measured in meter / sec 3.0E8 m/s

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inverse relation

answer

(wavelength)(frequency) = speed of light

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Quantum Theory

answer

-Energy is gained or lost in whole number multiples of the quantity hv (plank's Constant & an integer) /E= nhv

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quanta

answer

energy is transferred to matter in packets of energy

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Planck's constant

answer

h = 6.626E-34 (J)(s)

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Gamma

answer

Wavelength =10⁻¹² m

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X-Rays

answer

Wavelength = 10⁻¹⁰ m

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UV

answer

Wavelength = 10⁻⁸ m

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Visible

answer

4 to 7 x 10⁻⁷ m blue green yellow orange red wavelength increases frequency decreases energy decreases

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IR

answer

Wavelength = 10⁻⁴ m

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Micro

answer

Wavelength = 10⁻² m

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Radio

answer

FM --> wavelength = 1 short --> wavelength = 10² AM --> wavelength = 10⁴

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Particle Nature of Matter

answer

1. EM radiation is a stream of particles - photons 2. Energy and mass are inter-related Einstein

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Dual Nature of Light

answer

1. light travel through space as a wave 2. light transmits energy as a particle 3. particle's have wavelength, exhibited by diffraction patterns -large particles have very short wavelengths -all matter exhibits both particle and wave properties de Broglie

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Photoelectric Effect

answer

-when light strikes a metal surface, electrons are ejected -if the threshold frequency has been reach, increasing the intensity only increases the number of electrons ejected -if the frequency is increased, the ejected electrons will travel faster

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Continuous spectra

answer

contains all wavelengths of light

question

Emission spectra

answer

Bright Line Spectra 1. excited electrons in an atom return to lower energy states 2. Energy is emitted in the form of a photon of definite wavelength 3. Definite change in energy corresponds to: -definite frequency -definite wavelength 4. Only certain energies are possible within any atom

question

Absorption Spectra

answer

-A spectrum of electromagnetic radiation transmitted through a substance, showing dark lines or bands due to absorption of specific wavelengths -when electrons get excited they absorb light

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Bohr Model

answer

Quantum model 1. The electron moves around the nucleus only in certain allowed circular orbits 2. Bright line spectra confirms that only certain energies exist in the atom, and atom emits photons with definite wavelengths when the electron returns to a lower energy state 3. Energy levels available to the electron in the hydrogen atom n = an integer Z = nuclear change J = energy

question

Calculating the energy of the emitted photon

answer

1. calculate electron energy in outer level 2. calculate electron energy in inner level 3. calculate the change in energy (/E) /E = energy of final state - energy of initial state 4. use the equation to calculate the wavelength of the emitted photon

question

Energy Change in Hydrogen Atoms

answer

1. Calculate energy change between any two energy levels

question

Shortcomings of the Bohr model

answer

1. Bohr's model does not work for atoms other than hydrogen 2. Electron's do not move in circulate orbits

question

The Quantum Mechanical Model of the Atom

answer

The electrons as a standing wave 1. Standing waves do not propagate through space 2. Standing waves are fixed at both ends 3. Only certain size orbits can contain whole numbers of half wavelength (fits the observation of fixed energy quantities "quanta")

question

The Shrodinger Equation

answer

1. for the motion of one particle, along the x axis in space: 2. Solution of the equation has demonstrated that E (energy must occur in integer multiples 3. General equation: H = a set of mathematical functions "operator" = a wave function

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orbitals

answer

specific wave functions 1. Are not circular orbits for electron 2. are areas of probability for locating electrons

question

Heisenberg Uncertainty Principle

answer

1. There is a fundamental limitation on how precisely we can know both the position and momentum of a particle at a given time 2. The more accurately we know the position of any particle, the less accurately we know its momentum, and vice-versa

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Physical Meaning of a Wave Function

answer

1.Square of the absolute value of the wave function gives a probability distribution 2. Electron density map indicates the most probable distance from the nucleus 3. Do not describe -how an electron arrived at its location -where the electron will go next -when the electron will be in a particular location

question

principal quantum number (n)

answer

-integral values: 1, 2, 3.... -indicates probable distance from the nucleus higher numbers = greater distance = less tightly bound = higher energy

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angular momentum quantum number (l)

answer

orbital quantum number -integral values from 0 to n - 1 for each principal quantum number n -indicate the shape of the atomic orbitals

question

magnetic quantum number (ml)

answer

-integral values from l to -l, including zero -related to the orientation of the orbital in space relative to the other orbitals

question

spin quantum number (ms)

answer

-an orbital can hold only two electrons, and they must have opposite spins -spin can have two values, +1/2 & -1/2

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nodes

answer

internal regions of zero probability

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electron configuration

answer

1s→2s→2p→3s→3p→4s→3d→4p→5s→4d→5p→6s→ 4f→5d→6p s = 1 / p = 3 / d = 5 / f = 7

question

size of orbitals

answer

-defined as the surface that contains 90% of the total electron probability -orbitals of the same shape grow larger as n increases

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s Orbitals

answer

-spherical shape -nodes (s orbitals of n=2 or greater)

question

p Orbitals

answer

-two lobes each -occur in levels n=2 and greater Each Orbital lies along an axis (2px, 2py, 2pz)

question

d Orbitals

answer

-occur in levels n=3 and greater -two fundamental shapes 1. four orbitals with four lobes each, centered in the plane indicated in the orbital label (dxz, dyz, dxy, dx²-y²) 2. fifth orbital is uniquely shaped - two lobes along the z-axis and a belt centered in the xy plane (dz²)

question

f orbitals

answer

-occur in levels n=4 and greater -highly complex shapes -not involved in bonding in most compounds

question

energy level shifting

answer

-for many electron atoms, electron repulsion's increase energy, causing orbitals to "overlap" -d orbitals shift 1 level -f orbitals shift 2 levels

question

degenerate orbitals

answer

all orbitals with the same value of n have the same energy (hydrogen only)

question

ground state

answer

lowest energy state

question

excited state

answer

when the atom absorbs energy, electrons may move to higher energy orbitals

question

Pauli Exclusion Principle

answer

in a given atom no two electrons have have the same set of four quantum numbers

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Polyelectronic Atoms

answer

Internal Atomic energies 1. kinetic energy of moving electrons 2. potential energy of attraction between nucleus and electrons 3. potential energy of repulsion between electrons Electronic Correlation Problem 1. Electron pathways are not known, so electron repulsive forces cannot be calculated exactly 2. we approximate the average repulsion's of all other electrons

question

screening or shielding

answer

1. electrons are attracted to the nucleus 2. electrons are repulsed by other electrons 3. electrons would be bound more tightly if other electrons weren't present

question

variations in energy within the same quantum level

answer

1. atoms other than hydrogen have variations in energy for orbitals having the same principle quantum number 2. electrons fill orbitals of the same n value in preferential order -Ens < Enp < End < EnF 3. electron density profiles show that s electrons penetrate to the nucleus more than other orbital types -closer proximity to the nucleus = lower energy

question

Aufbau Principle

answer

as protons are added one by one to the nucleus to build up elements, electrons are similarly added to these hydrogen-like orbitals

question

Hund's Rule

answer

The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of degenerate orbitals

question

valence electrons

answer

-electrons in the outermost principle quantum level of an atom -elements in the same group (vertical column) have the same valence electron configuration

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transition metals

answer

"d" block

question

lanthanide and actinde series

answer

-the sets of 14 elements following lanthanum and actinium -"f" block

question

representative elements

answer

-main-group -groups 1A through 8A -Configurations are consistent

question

Metalloids

answer

-semi-metals -found along the border between metals and nonmetals (stair-case) -exhibit properties of metals and nonmetals

question

Ionization energy

answer

the energy required to remove and electron from an atom -increases for successive electrons -increases across a period WHY? electrons in the same quantum level do no shield as effectively as electrons in inner levels -irregularities at half filled and filled sublevels due to extra repulsion of electrons paired in orbitals, making them easier to remove -decreases with increasing atomic number within a group WHY? electrons farther from the nucleus are easier to remove Multiple (I₂,I₃...) and "jumps": taking away more than one electron -more energy to take second electron than first // core electron take massive amounts of energy

question

Electron Affinity

answer

the energy change associated with the addition of an electron -increases across a period -decreases down in a period WHY? electrons farther from the nucleus experience less nuclear attraction -some irregularities due to repulsive forces in the relatively small p Orbitals

question

Atomic Radius

answer

1. determination of radius -half of the distance between radii in a covalently bonded diatomic molecule "covalent atomic radii" 2. Periodic Trends -decreases across a period WHY? increased effective nuclear charge due to decreased shielding -increase down a group WHY? addition of principal quantum levels

question

alkali metals

answer

1. easily lose valence electrons (reducing agents) -react with halogens to form salts -react violently with water (Lithium is not the more reaction because the heat of reaction is insufficient to melt lithium and expose all of its surface area 2. Large hydration energy -positive ionic charge makes ions attract to polar water molecules 3. Radius and Ionization energy follow expected trend

question

Ion size compared to Atom size

answer

metals -decreases WHY? less electrons but same number of protons pulling non-metals -increase WHY? proton:electron ratio smaller

question

metallic properties

answer

ability to loose electrons (shiny, condubility, malleability) -across a period --> decreases -down a family --> increases WHY? valence electrons far from nucleus

question

non-metallic properties

answer

ability to gain electrons -across a period --> increases -down a family --> decreases

question

Electronegativity

answer

ability to attract a shared electron in a bond Fluorine - 4.0 Fr +Cs ~~ .7 (non-metal)

question

Atomic structure

answer

Protons, Neutrons, and Electrons.

question

Periodicity

answer

the quality of recurring at intervals

question

Electromagnetic

answer

pertaining to or exhibiting magnetism produced by electric charge in motion

question

Radiation

answer

(medicine) the treatment of disease (especially cancer) by exposure to radiation from a radioactive substance

question

wavelengths

answer

physical energy

question

Frequency

answer

the number of observations in a given statistical category

question

Energy

answer

an imaginative lively style (especially style of writing)

question

Speed is constant

answer

2.99792458 x 10^8 m/s

question

Nature

answer

the essential qualities or characteristics by which something is recognized

question

Matter

answer

that which has mass and occupies space

question

Max Planck

answer

German physicist whose explanation of blackbody radiation in the context of quantized energy emissions initiated quantum theory (1858-1947)

question

Quantum Theory

answer

(physics) a physical theory that certain properties occur only in discrete amounts (quanta)

question

Planck's constant

answer

h= 6.626 x 10^-34 J S

question

photons

answer

light quanta

question

atomic mass

answer

(chemistry) the mass (in atomic mass units) of an isotope of an element

question

Density

answer

mass/volume

question

Volume

answer

physical objects consisting of a number of pages bound together

question

Speed

answer

distance travelled per unit time

question

Frequency

answer

the number of observations in a given statistical category

question

Energy

answer

(physics) the capacity of a physical system to do work

question

Orbital

answer

of or relating to an orbit

question

Shapes

answer

used to enhance a publication and convey meaning

question

Atom

answer

(physics and chemistry) the smallest component of an element having the chemical properties of the element

question

Atomic radius

answer

one-half the distance between the nuclei of identical atoms that are bonded together

question

Hydrogen

answer

a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas

Chemistry: Chapter 7: Atomic Structure & Periodicity – Flashcards

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