Chapter 5: Models of the Atom 2019

What is the maximum number of electrons in the first 3 sub-levels?

1st: 2, 2nd: 8 3rd: 18

Niels Bohr

Danish physicist who studied atomic structure and radiations; developed the quantized orbit model of the atom, electrons can only reside in certain energy levels.

Cloud model

Electrons move rapidly within a cloud like region around the nucleus.

Give the electron configuration for a neutral atom of Oxygen

First find the atomic number of Aluminum. Then use the aubau or diagonal rule to build an electron configuration up to that number. 1s2 2s2 2p4

Give the electron configuration for a neutral atom of Magnesium

First find the atomic number of Aluminum. Then use the aubau or diagonal rule to build an electron configuration up to that number. 1s2 2s2 2p6 3s2

Give the electron configuration for a neutral atom of Aluminum.

First find the atomic number of Aluminum. Then use the aubau or diagonal rule to build an electron configuration up to that number. 1s2 2s2 2p6 3s2 3p1

What happens when an electron moves from a higher energy to a lower energy level?

It halves it's energy

Bohr Model

Model of the atom in which electrons move rapidly around the nucleus in paths called orbits

Which scientist developed the quantum mechanical model of the atom?

Neihls Bohr

The amount of energy required to move an electron from one energy level to another energy level.

Quantum

Which type of wave has the lowest frequency?

Radio Waves

What was inadequate about Rutherford's atomic model?

Rutherford's atomic model could not explain the chemical properties of elements.

Rutherford Model

The atom has a small, dense, positively charged nucleus. Electrons move around the nucleus.

5.2 Three rules- ___________________________ -tell you how to find the electron configurations of atoms.

The aufbau principle, the Pauli exclusion principle, and Hund's rule

In the Bohr Model, where are the electrons and protons located?

The electrons move around the protons, which are the at the center of the atom.

Energy Sublevels

The energy levels contained within a principal energy level.

Electron ladder

The energy levels in atoms are unequally spaced; The higher energy levels are closer together.

Energy Levels

The rings of the electron orbits (clouds) that hold electrons.

Aufbau Principle

The rule that electrons occupy the orbitals of lowest energy first

Each energy sublevel corresponds to an orbital of:

a different shape, which describes where the electron is likely to be found.

atomic orbital

a mathematical expression describing the probability of finding an electron at various locations; usually represented by the region of space around the nucleus where there is a high probability of finding an electron

photon

a quantam of light, a discrete bundle of electromagnetic energy that interacts with matter similarly to particles

atomic orbital

a region of space in which there is a high probability of finding an electron.

emission spectrum

a series of bright lines of particular wavelengths produced by a vapor under low pressure.

pauli exclusion principle

an atomic orbital may describe at most two electrons, each with opposite spin direction

5.1 Each sublevel of a principal energy level corresponds to

an orbital shape describing where an electron is likely to be found.

Bohr changed Rutherford's model to include newer discoveries about how the energy of an atom:

changes when it absorbs or emits light.

5.3 Classical mechanics adequately describes the motions of bodies much larger than atoms, while quantum mechanics

describes the motion of subatomic particles and atoms as waves.

5.3 The light emitted by an electron moving from a higher to a lower energy level has a frequency

directly proportional to the energy change of the electron.

hund's rule

electrons occupy orbitals of the same energy in a way that makes the number of electrons with the same spin direction as large as possible

electromagnetic radiation

energy waves that travel in a vacuum at a speed of 2.998 X 10^8 m/s; includes radio waves, microwaves, infrared waves, visible light, ultravioleet waves, X-rays, and gamma rays

5.1 Rutherford's planetary model could not

explain the chemical properties of elements

5.1 The quantum mechanical model determines the allowed energies an electron can have and

how likely it is to be found in various location around the nucleus.

The *quantum mechanical model* determines the allowed energies an electron can have and:

how likely it is to find the electron in various locations around the nucleus.

5.3 The wavelength and frequency of light are

inversely proportional to each other.

heisenberg uncertainty principle

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

Different atomic orbitals are denoted by:

letters. s-orbitals are spherical. p-orbitals are dumbbell-shaped. d-orbitals are clover-leaf-shaped. f-orbitals are complex in shape.

5.3 When atoms absorb energy the electrons move to higher energy levels. These electrons then

lose energy by emitting light when the electrons drop back to lower energy levels.

5.2 Some actual electron configurations differ from those assigned using the aufbau principle because half-filled sublevels are

not as stable as filled sublevels, but they are more stable than other configurations.

The energy levels of electrons are labeled by

principal quantum numbers n = 1,2,3,4...

The modern description of the electrons in atoms States that electrons do not travel in defined orbits but rather are localized into orbitals.

quantum mechanical model

For each principal energy level, there may be several orbitals with different:

shapes and at different energy levels. These energy levels within a principal energy level constitute *energy sublevels*.

5.1 Bohr Proposed that an electron is found only in

specific circular paths, or orbits, around the nucleus

Bohr proposed that an electron is found only in:

specific circular paths, or orbits, around the nucleus.

What is the shape of the 3p atomic orbital?

spherical

quantam

the amount of energy needed to move an electron from one energy level to another

electron configurations

the arrangement of electrons of an atom in its ground state into various orbitals around the nuclei of atoms

wavelength

the distance between adjacent crests of a wave

amplitude

the height of a wave's crest

ground state

the lowest possible energy of an atom described by quantam mechanics

quantam mechanical model

the modern description, primarily mathematical, of the behavior of electrons in atoms

frequency

the number of wave cycles that pass a given point per unit of time

atomic emission spectrum

the pattern formed when light passes through a prism or diffraction grating to separate it into the different frequencies of light it contains

aufbau principle

the rule that electrons occupy the orbitals of lowest energy first

energy levels

the specific energies an electron in an atom or other system can have

hertz

the unit of frequency, equal to one cycle per second

spectrum

wavelengths of visible light that are separated when a beam of light passes through a prism; range of wavelengths of electromagnetic radiation