chapter 5 overview

subatomic particles

The early 1900s brought discovery of __.

Rutherford

__ proposed a model where most of an atoms mass and all the positive charge was in the nucleus.

arranged

Rutherford's model did not explain how electrons __ around the nucleus.

emission of light

They discovered that an element's chemical behavior is related to the arrangement of the electrons in its atoms through the __.

electromagnetic radiation

a form of energy that exhibits wavelike behavior as it travels through space

light

\___ is part of the electromagnetic spectrum

wavelength

is the distance between identical points on successive waves

amplitude

is the vertical distance from the midline of a wave to the peak or through

frequency

the number of waves that pass though a particular point in 1 second (Hz= 1cycle/s)

3.00 x 10 (8)

speed of light in a vacuum

colors; frequencies

different __ mean different __ and wavelengths being emitted.

Maxwell

__ proposed that visible light consists of electromagnetic waves. (1873)

different wavelengths

This wave model could not explain the emissions of __.

Max Planck (1858-1947)

__ researched this and concluded that matter can gain or lose energy only in small, specific amounts called quanta.

quantum

the minimum amount of energy that can be gained or lost by an atom

Planck's constant is h

h= 6.63 x 10 (-34) J.s

photoelectric effect

electrons are emitted from a metal's surface when light of a certain frequency or higher than a certain frequency, shines on the surface.

Einstein

"Photoelectric Effect" was solved by __ in 1905

1. wave nature 2. particle nature

Light has both : 1.___ and 2.___

photons

a massless particle that carries a quantum of energy

atomic spectrum

of an element is the set of frequencies of the electromagnetic waves emitted by atoms of the element

intense flame or electricity

electrons

Parts of the atomic spectrum:

All elements emit light when vaporized in an __ or when __ is passed through their gaseous state.

When in a flame or electricity is passed,, __ absorb energy and then give off energy in the form of light.

Niels Bohr (1885-1962)

__ was the first who saw the connection between the wavelengths an element emits and its atomic structure.

quantized

Bohr postulated that to get spectral lines, the energy of the electron in the atom must be __ (specific amount of energy)

hydrogen atom

Bohr used Rutherford's planetary model to develop a model of the __.

orbits; energy

In Bohr's atom, electrons move around the nucleus in __ that possessed different amounts of __.

quantum number (n)

each orbit was identified by a __.

ground state

lowest energy level, n=1, closest to the nucleus

excited state

a level of higher energy, n=2 or greater

absorb

electron could __ energy and jump to a higher energy level

1. e can only have specific (quantized) energy values

2. light is emitted as e moves from one energy level to a lower energy level

3. From ground state (lowest energy) to the excited state (higher energy)

Bohr's model of the atom (1913) in which three rules.

failed to explain the spectrum of any other element

not explain the chemical behavior of atoms

Bohr's model explained the hydrogen atom, but it__.

It also failed in __.

developed the idea of quantized energy levels and laid the groundwork for atomic models.

Bohr's model was incorrect but it__.

He answered the question of why electrons must be restricted to specific distances from the nucleus.

What did Louis de Broglie contribute? (he was french)

particle and a wave

In 1924, De Broglie reasoned that e is both a __ and __.

mass and velocity

He derived a mathematical relationship between the __ and __ of a moving particle and the wavelength that it would exhibit.

wavelength symbol=h/mv

De Broglie formula

wavelengths, frequencies, and energies

De Broglie's conclusion was that electrons and other moving particles do have wavelength characteristics. If an electrons has a wavelike motion and is restricted, only certain ___ are possible.

Heisenberg Uncertainty Principle

states that it is impossible to know precisely both the velocity and position of a particle at the same time

probability; region

The only quantity that can be known is the __ for an electron to occupy a certain __ around the nucleus.

Schrodinger

In 1926, __ derived an equation that described both the particle and wave nature of the electron of a hydrogen atom.

of other elements

Schrodinger's new atomic model applies equally well to atoms __.

quantum mechanical model

Electrons have no precise orbits

Electrons exist in certain region surrounding the nucleus.

The region around the nucleus can be described as a blurry cloud of negative change

electron density

the density of an electron cloud

atomic orbital

a region around the nucleus of an atom where an electron with a given energy is likely to be found

principle quantum number (n)

indicates the main energy levels surrounding the nucleus. It symbolized by n, and is a whole number 1-7.

The Angular Momentum Quantum Number (l)

indicates the shape of an orbital. These are represented by s, p, d, f

the magnetic quantum number (ml)

this is the orientation of the orbital in three-dimensional space

electron spin

electrons have a spin of clockwise or counter clockwise.

electron configuration

it is the distribution of electrons among the orbitals of an atom

It describes where the electrons are found and what energy they posses.

It is an address for electrons

electron address

An __ consist of principle quantum number and it's orbital quantum number.

Aufbau principle

electrons are added one at a time to the lowest energy orbitals available until all the electrons of the atom have been accounted for.

Pauli Exclusion principle

an orbital can hold a maximum of 2 electrons and they must spin in opposite direction.

Hund's rule

the electrons occupy energy orbitals so that a maximum number of unpaired electrons results.

orbital diagram

is a visual representation of electron configuration

uses lines or boxes to represent the orbital

uses arrows to represent electrons

electrons configuration- uses numbers, letters, and superscripts (electrons)

valence electrons

the electrons the outermost shell that are responsible for an atom's chemical behavior

short-hand electron configuration

focuses on valence electrons (configuration)

uses noble gases in brackets and then the valence electron configuration ex. Li= [He]2s(1)

s-block

group 1a and 2a

p-block

group 3a to group 8a

d- block

transition metals, the middle of the periodic table

f- block

innertransition metals, the two rows under the table

electron dot structure

consists of the element's symbol surrounded by dots

The element's symbol represents the atomic nucleus and inner-level electrons

The dots represents the atom's valence electrons

In writing an atom's electron dot structure, dots are placed one at a time on the four sides of the symbol and then paired up until all are used.

okay

Do not forget to study the math proportion of the test. IMPORTANT TO KNOW!!! Type in "okay" to get the answer correct

Frequencies

Bohr's model of the atom predicted the __ of the lines in hydrogen's atomic emission spectrum.

Lower

According to Bohr's atomic model, the smaller an electron's orbit, the __ the atom's energy level

Higher

According to Bohr's atomic model, the larger an electron's orbit, the __ the atom's energy level.

Electron

Bohr proposed that when energy is added to a hydrogen atom, it's __ moves to a higher-energy orbit

Energy levels

According to Bohr's atomic model, the hydrogen atom emits a photon corresponding to the difference between the __ associated with the two orbits it transitions between.

Atomic emission spectrum

Bohr's atomic model failed to explain the __ of elements other than hydrogen c

Quantum mechanical model of the atom

The modern model of the atom that treats electrons as waves

Atomic orbital

A three-dimensional region around the nucleus representing the probability of finding an electron

Schrödinger wave equation

Originally applied to the hydrogen atom, it led to the quantum mechanical model of the atom

Do not

Atomic orbitals __ have an exactly defined size

Two

Each orbital may contain at most __ electrons

Spherically shaped

All s orbitals are __

Ground state

The lowest allowable energy state of an atom is called its __

n

A principal energy has __ energy sub levels

Orbitals

The maximum number of __ related to each principal energy level equals 2n*2

Three

There are __ equal energy p orbitals.

2s and 2p

Hydrogen's principal energy level 2 consists of __ orbitals.

Three?

Hydrogen's principal energy level 3 consists of __ orbitals.