chemistry exam 4

what type of radiation is light

electromagnetic

what are some different types of electromagnetic radiation

X-Rays, UV radiation, Infrared radiation

what are the different properties of electromagnetic radiation

waves and particles

what are the different descriptors that are used to describe waves

wavelength, frequency, amplitude, and velocity.

Wavelength

the distance between two peaks on a wave

Frequency

the number of wave peaks that occur in a given amount of time. Abbreviation is n Usual unit is Hertz (Hz), which means "per second".Sometimes also see s-1.

Amplitude

the height of a wave, measured from the baseline to the peak.

What is the speed of light in meters per second?

3.00 x 10^8 m/s

What is the abbreviation for the speed of light?

c

What is true about the velocity of all electromagnetic waves?

The velocity of all EM waves is constant.

For all EM radiation what is the constant speed ?

3.00 x 10^8 m/s

Blackbody radiation

As an object is heated, it gives of EM radiation/ the light given off by a hot object

The Photoelectric Effect

Electrons are given off when certainsubstances are struck by light

Emission spectra

when the electrons of a gas are excited, the gas gives off certain wavelengths of light

photon

a particle of light

quantum

The amount of energy contained in a photon

what prediction does blackbody radiation give us

that all objects should glow in the dark, even when cool

what is the incorrect prediction that states all objects should glow in the dark, even when cool known as

ultraviolet catastrophe

who proposed the particle nature

Max Planck

what did max planck state about blackbody radiation

that energy can only be released or absorbed in discrete chunks of some minimum size

what is the frequency of quantum light

E = hv

Planck's constant

6.626 x 10^-34

who was the first to explain the photoelectric effect

Albert Einstein

what did Einstein state about the Photoelectric effect

the light hitting the surface was behaving as a particle, which he called a photon

what was the equation used to determine the energy of the photon Einstein was describing

Planck equation: E=hv

what happen when a photon strikes a surface

its energy is transferred tothe material

binding energy

certain amount of energy needed to cause an electron to be ejected.

what happens if the amount of energy of the binding energy is greater than the energy of the photon

no electrons are ejected.

what happens if the energy of the photon is greater than the binding energy

an electron is ejected.

spectrum

the set of wavelengths given off (orabsorbed) by a material

what are the 2 types of spectrums

continuous or line

continuous spectrum

contains all the wavelengths overthe wavelength range being studied.

line spectrum

A spectrum consisting of only a few discrete wavelengths of light

The Bohr Model

1. Only orbits of certain radii, corresponding to certain energy, are allowed

2. An electron has a specific energy while in a specific orbit, and will not radiate energy while in that state.

3. Absorption or emission of energy only occurs when an electron moves from one energy state to another

what happens as the energy level goes up

The difference between the energy levels gets smaller.

Uncertainty Principle

states that we cannot know exactly the location and momentum of an electron at the same time

who developed equations which model electrons both as particles and as waves

Erwin Schrödinger

the uncertainty principle is based on what

the probability of the position a electron will be

What are the 4 quantum numbers?

n, l, ml, ms

what does n stand for

the principal quantum number, Describes the size of the orbital

what does l stand for

the angular momentum quantum number, Describes the shape of the orbita

what does ml stand for

The magnetic quantum number, Describes theorientation of the orbital.

what happen as n (l) increases

the orbital becomes bigger, and the electron is farther away from the nucleus, and the energy associated with the orbital becomes more positive

what is the shape of a s orbital

spherical

what is a node

A region where the probability of finding an electron goes to zero that is between two areas where an electron could be found

what shape is a p orbital

dumbbell/infinity sign

at what degree can a p orbital be centered at

90 degrees

what shape are d orbitals

clover

what does ms describe

the spin of electron/ the orientation of the electron

electron configuration

The way in which electrons are distributed in the orbitals of an atom

ground state

the most stable electron configuration

Hund's Rule

For degenerate orbitals, the lowest energy state (most stable) is obtained when the number of electrons with the same spin is maximized.

what is the primary driving force of Hund's rule

electrostatic repulsion between electrons

What type of charge do electrons have?

negative

valence electrons.

Electrons in the outermost shell of an atom.

core electrons

The electrons that are not in the innermost shell of an atom.

in the earliest version of the periodic table, how were the elements classified

by atomic weight

who created the modern periodic table

Dmitri Mendeleev

atomic number

the number of protons in an atom

effective nuclear charge (Zeff)

average environment created by the nucleus and the other electrons in the atom

As we move across the periodic table from left to right, what happens to (Zeff)

it increases

As we go down a column, what happens to Zeff

it stays constant

as we go down the periodic table, what happens to the atomic radius

it increases

as we go across the periodic table, what happens to the atomic radius

it decreases

ionic radius

refer to the radius of the ion after electron(s) have been added or removed

ionization energy

the energy required toremove an electron from an atom

The higher the ionization energy......

the more difficult it is to remove an electron.

as we go across the periodic table from left to right, ionization energy

increases

as we go down the periodic table, ionization energy

decreases

electron affinity

is the change in energy when an electron is added to anatom or ion

chemical bond

the force that holds the atoms in position in a substance.

types of chemical bond

ionic, covalent, metallic

ionic bond

are formed by the electrostatic interaction between ions. Ions are formed when electrons are transferred from one atom to another. Generally found between a metal and a nonmetal.

Covalent bonds

formed when atoms "share" electrons. Generally found between nonmetals.

Metallic bond

Each atom is bonded to its neighbors; electrons are shared throughout the lattice. Generally found between metals

what do chemical bonds depend on

he position ofelectrons in the atoms involved in bonding

Lewis dot symbol

used to illustrate the number of valence electrons

The octet rule

the tendency of atoms to form an octet of valence electrons

what are ionic bonds based on

the attraction between ions of opposite charge.

Ionic bonds are formed between....

metals and nonmetals

Lattice Energy

The energy released when the lattice is formed/the energy required to separate a mole of an ionic solid into its gaseous ions

what is lattice energy based on

The potential energy of two interacting charged particles

polyatomic ions

ions consisting of more than one atom bonded together

nonpolar covalent bond

Bonds where the electrons are shared equally

polar covalent bond

One atom exerts a greater "pull" on the electrons than the other

Electronegativity

defined as the ability of an atom to attract electrons to itself in a molecule.

what is the most electromagnetic element

Fluorine (F)

what is the least electromagnetic element

cesium (Cs)

What happens if the difference in electronegativity between two atoms is less than 0.5?

the bond is considered nonpolar covalent.

What happens if the difference in electronegativity between two atoms is between 0.5 and 2.0

The bond is considered polar covalent

what happens if the difference in electronegativity between two atoms is greater than 2.0

the bond is considered ionic

if there are 4 electron groups, what shape will they rearrange themselves in

tetrahedron

what is the degree of a linear electron domain

180

what is the degree of a trigonal planar electron domain

120

what is the degree of a tetrahedral electron domain

109.5

what is the degree of a trigonal bipyramidal electron domain

120 and 90

what is the degree of a octahedral electron domain

90

vector

a quantity that has both magnitude and direction

what is a example of a polar molecule

water

how do covalent bonds occur

when atoms share electrons