Chapter 4 Flashcards
How many nanometers in a meter
1 nanometer - 10^-9 meters
1 meter - 10^9 nanometers
What is the speed of light (c)
3.00x10^8 m/s
What is electromagnetic radiation
- a form of energy that travels in waves that are produced when charged particles move or vibrate relative to each other
- exists in small increments- photons
Electromagnetic spectrum
From low frequency, long wavelength to high frequency short wavelength:
Radio- Microwave- Infared- visible- UV- X-rays- Gamma rays
Visible spectrum
The middle of the electromagnetic spectrum, a narrow range of radiation that our eyes can detect, we perceive it as visible light.
Wavelength, Lambda (λ)
The distance from a point on one wave cycle to the same point on the next cycle. Typically measured in meters or nanometers.
Frequency, nu (ν)
The number of waves that pass through a point in one second.
What is 1 Hertz (Hz) equal to
1 wave/ second
Three ways that 10,000 waves can be written
10,000 Hz, 10,000/ s, 10,000 s^-1
How are wavelength and frequency related to eachother
inversely
- Wavelength decreases, frequency increases
- Frequency decreases, wavelength increases
relationship of wavelength and frequency described mathematically
c=λν
Speed of light = Wavelength x Frequency
units: m/s = m x 1/s
Energy of light depends on
Frequency and wavelength
longer wavelength, lower frequency-less oscillations thus lower energy
Shorter wavelength, higher frequency- more oscillations thus higher energy
Energy of a photon (equation)
E=hν
Energy=Plank’s Constant x Frequency
J = J*s x 1/s
Planks Constant
6.63x10^-34 J*s
Energy of a photon in terms of wavelength
Energy of a photon: E= hv
v= c/λ
E= hc/λ
Bohr Model
The electrons orbit the nucleus like planets orbit the sun when an electron absorbs light it jumps to a higher energy level. when it drops to a lower energy level it releases energy as light.
line spectra related to the light produced when electrons drop to lower levels
Quantum Model
Describes electrons by: -energy -possible location Main Ideas: -the uncertainty principle -wave nature of electrons
Heisenberg’s uncertainty principle
The principle deals with velocity, mass, and location of subatomic particles
A central idea: It is impossible to precisely know the exact velocity and location of a particle.
Quantum mechanics
describes electrons in terms of their probable locations or their energies
(We describe them by the shape they occupy.)
The wave nature of electrons
Tiny, fast moving particles also behave as waves
Four rules of configuration of electrons within the atom.
1) Electrons occupy different energy levels
2) Each energy level contains one or more sublevels
3) Each sublevel contains one or more orbitals
4) Each orbital holds up to two electrons
Principle quantum number, n
the id of dif levels that electrons occupy (n = 1, 2,3)
The lowest energy level (1) lies closest to the nucleus
Electron capacity of levels of an electron
Level Electron Capacity
1 2
2 8
3 18
4 32
the four common (sublevels) energy levels, in order
s, d, p, f
each sublevel can hold a set number of electrons
Orbital
a region where electrons are most likely to be found
Number of orbitals in each sublevel
s - 1
p - 3
d - 5
f - 7
Level one sublevel(s), # of orbitals, and electron capacity
One sublevel (s), one orbital, capacity of two electrons
Level two sublevel(s), # of orbitals, and electron capacity
Two sublevels (s, p), three orbitals, capacity of eight electrons
Level three sublevel(s), # of orbitals, and electron capacity
Three sublevels (s, p, & d), five orbitals, capacity of eighteen electrons
Level four sublevel(s), # of orbitals, and electron capacity
Four sublevels (s, p, d, & f), seven orbitals, capacity of 32 electrons
Energy level growth pattern
With each new level is an additional sublevel, two orbitals, and four electrons
Order of energy in sublevels
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d. 5p etc
Which two sublevels form an atom’s valence
s & p
Max # of electrons in the highest energy level of an atom, which sublevels do these occupy
8 electrons max and s & p sublevels
Spin
The magnetic fields of electrons, oriented in oppisite directions
Hund’s Rule
If orbitals of the same energy level are available, electrons singly occupy orbitals rather than paring together.
Valence level
The highest occupied energy level
Octet Rule
An atom is stabilized by having its highest occupied (valence) level filled.
Isoelectronic
When ( ) have the same electron configuration
Way of telling how many valence electrons an atom has
the number of valence electrons corresponds with the number of the 1A-8A columns (exa: column 3A, 3 valence electrons)
