Chemistry Unit 4: Electronic Structure of an Atom

Frequency

The number of cycles that pass through a point per second

Amplitude

the height of a wave from the origin to a crest or a trough

Electromagnetic Spectrum

All frequencies and wavelengths of electromagnetic radiation

Quantum

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

Planks Constant

6\.626x10^-34 J/s

Photoelectric Effect

Phenomenon where electrons are emitted from a metal’s surface when light of a certain frequency shines on the surface

Photon

A particle of electromagnetic radiation that has no mass, and carries a quantum of energy

Atomic emission spectrum

Set of frequencies of electromagnetic waves emitted by atoms of an element

As wavelength increases the frequency….

decreases

As wavelength decreases the frequency…

increases

Speed and amplitude of light are not affected by…. and frequency

wavelength

What relationship is there between wavelength and frequency?

Inverse relationship

What relationship is there between photons and wavelength/frequency?

Direct relationship

What has more energy, red or blue light?

Blue light. The photon that corresponds to red light carries less energy than the photon that corresponds to blue light. The longer the wavelength of light the lower the energy of its photons

Orbitals

probability envelopes are regions of space where there is a high (90%) probability of finding an electron.

Each principal energy level is assigned a principal quantum number…

n

The lowest principal quantum number….is assigned to the smallest and lowest energy level immediately next to the nucleus

n=1

with…value of n, the principal energy levels get larger and are higher in energy and further away from the nucleus

increasing

Each principal energy level is made up of energy sublevels……

ns,np,nd,nf,etc

Energy sublevels consist of….

orbitals

An energy sublevel is a group of orbitals with …energy but …… orientation

similar, different

s-sublevel

Each energy level has an s-sublevel from n=1-∞

p-sublevel

All energy levels n=2 and higher have p-sublevels. There are 3 orientations in space corresponding to 3 orbitals per p-sublevel

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d-sublevel

All energy levels n=3 and higher have d-sublevels. There are orientations, corresponding to 5 orbitals per d-sublevel. 4 orientations look like a clover, one is nicknamed the donut whole.

f-sublevel

All energy levels n=4 and higher have f-sublevels. There are 7 orientations, corresponding to 7 orbitals per f-sublevel. Complex shape.

What energy level is this?

An ns sub-level where n=1-∞

What energy level is this?

An np sub-level where n=2-∞

What energy level is this?

An nd sub-level where n=3-∞

What does an nf energy sublevel look like?

A complex shape

Aufbau principle

Electrons are placed in the lowest energy sublevels.

Sublevels are added in order of increasing…….Larger energy levels, with more sublevels, are higher in energy and further away from the nucleus

energy

Pauli’s Exclusion Principle

States that each atomic orbital can hold a maximum of two electrons with opposite spins. Electrons act like a tiny magnet, so if two have the same poles line up, they repel each other and move in directions to realign. Therefore opposite spins overcome repulsive forces

Hund’s Rule

Which states that for a set of orbitals of similar energy, each orbital must be filled singly with parallel spins before electron paring can occur

S-block elements are those with their…..in the ns subshell

valence electrons

d-block elements are the….. block of the periodic table in which the valence electrons enter the inner d sub-shell

middle

p-block elements are those with their valence electrons in the np sub-shell. These are all the elements in groups…

13-18

Closed configuration

A configuration in which ns and np sub-shells are filled is called a closed configuration

Ground state electron configurations are the… possible energy states, written by following the increasing energy order of energy levels according to the Aufbau principle

lowest

The excited state is a state of a ….. energy that an atom attains by absorbing energy from its surroundings

higher

atoms can have…. excited states

multiple

The excited state for an atom would correspond to the placement of electrons in…. energy levels than that allowed for the ground state

higher

Octet Rule

Atoms become energetically stable by attaining a full valence shell. They do this either by forming a full octet or a full duet

If an atom gains electrons it acquires a ….. charge

negative charge.

Negatively charged ions are called anions and are…

non-metals

.If it loses electrons, it becomes… charged

positively

Positively charged ions are…

cations and are metals

Elements in Groups 1a,2a,3a…..1,2, and 3 electrons to become isoelectronic with the noble gas preceding them. These elements form…charged ions with charges of +1,+2, and +3.

lose

Elements in 5a,6a,7a,… 3,2, and 1 electrons to become isoelectronic with the noble gas proceeding them. These elements for negatively charged ions with charges of -3,-2, and -1 respectively

gain

period

horizontal across the periodic table (row of elements)

group/family

vertical up/down the periodic table (column of elements)

What does a column/family/group of elements have in common?

Same number of valence electrons

What does a period/row of elements have in common?

Same number of energy sublevels

What type of metal is column 1a?

Alkali Metals

What type of metal is column 2a?

Alkaline Earth Metals

What type of non-metal is column 3a?

Boron Family

What type of non-metal is column 4a?

Carbon Family

What type of non-metal is column 5a?

Nitrogen Family

What type of non-metal is column 6a?

Chakogens or Oxygens Family

What type of non-metal is column 7a?

Halogens

What type of non-metal is column 8a?

Noble Gasses

What are d block elements called?

transition metals

What are f block metals called?

intertransition metals