Unit 4: Electrons and Light

Energy Level

a region of an atom in which electrons of the same energy are likely to be found (the energy levels 1, 2, 3)

Subshell

A subdivision of an energy level in an atom. They are divided into orbitals. Subshell s, p, d, f

Orbital

In which the subshells are divided and are slots

Subshell s

1 orbital, maximum # of 2 electrons

Subshell p

3 orbitals, maximum # of 6 electrons

Subshell d

5 orbitals, maximum # of 10 electrons

Subshell f

7 orbitals, maximum # of 14 electrons

Energy level 1 (1st row)

Has subshell s and up to 2 electrons

Energy level 2 (2nd row)

Has subshell s (2 e-) and p (6 e-)

Energy level 3

Has subshell s (2 e-), p (6 e-), and d (10 e-)

Energy level 4

Has subshell s (2 e-), p (6 e-), d (10 e-), and f (14 e-)

Electron configuration

On the surface, showing the arrangement of the energy levels, subshell, and how many electrons in each subshell telling us, where a specific element is located.

Orbital notation

Another way of telling us where a specific element is located through a diagramic representation that uses arrows to show the specific location of each electron in its orbitals that is in each subshell and energy level.

Wavelength

Horizontal distance between the crests or between the troughs of two adjacent waves

Symbol: λ, which is called lambda

Common units: Meters, nanometers (nm)

Frequency

The number of complete waves that pass a given point in a certain amount of time

Symbol: nu (ν, f)

Common units: hertz (hz)

Relationship between wavelength and frequency

inversely proportional: increasing wavelenth, decreasing fequency; decreasing wavelength, increasing frequency

Relationship between energy and frequency

directly proportional: energy increases, frequency increases; energy decreases, frequency decreases

Visible light

electromagnetic waves that are visible to the human eye

Order of colors of visible lights based on its wavelength large to small

Red, Orange, Yellow, Green, Blue, Indigo, Violet

All electromagnetic radiation travels at the same speed of.....

light (c) which equals 3x10^6

Relationship between speed and wavelength/frequency

As wavelength gets shorter, the frequency increases, while the speed stays the same

Speed of light equation

c=λv

How does an element emit light

In an atom, the electrons absorb energy which makes them get excited allowing them to move up the energy rings. Then the excited electron falls back down, because of its attraction to the protons, releasing energy as light.

Columbic Attraction

The attraction between oppositely charged particles (+/-)

Why does the columbic attraction work the way it does?

The protons are positive and the electrons are negative, so the protons in the nucleus of an atom have attraction for the electrons surrounding the nucleus

How does the attractive forces vary

The attractive forces can be weak or strong depending on 2 things: the distance between the oppositely charged particles and the number of protons

The distance between the particles affect the attractive force

The farther the particles, the weaker the attractive force

The closer the particles, the stronger the attractive force

The number of protons affect the attractive force

The more the protons the stronger the attraction it has on the electrons

The fewer the protons the weaker the attraction it has on the electrons

Atomic radius

the (half) distance from the nucleus to the outer most electrons

Periodic trends on atomic radius

Atomic radius increases going down a group

- There are more rings at each energy level

Atomic radius decrease across a period

- The energy level stays the same but there are more protons which means there is a tighter hold on the electrons from the nucleus, making the distance between the two smaller

Diagnally up the atomic radius decreases and diagnally down it increase

Ionization energy

The amount of energy required to remove an electron from an atom

Periodic trends on Ionization energy

Ionization energy decreases down a group

- the atom is becoming larger --> the nucleus is furhter from the electrons, requiring less energy to overcome the force of attraction

Ionization energy increases across a period

- Since the atomic radius is getting smaller, the electrons are closer to the nucleus where the protons have a stronger force of attraction, more energy needed to overcome

Electronegativity

An atoms ability to attract an electron from a DIFFERENT atom

Periodic trends on Electronegativity

Electronegativity decreases down a group

- a greater distance between the nucleus and a different atom, causing a lower force of attraction, higher ability to pull an electron

Electronegativity increases across a period

- Since the atomic radius is getting smaller, the electrons are closer to the nucleus where the protons have a stronger force of attraction, making it be a lower ability to pull an electron off of a different atom