Chapter 9: Atomic and Nuclear Phenomena Flashcards
what are the colors that we see?
colors that are not absorbed
Photoelectric effect.
When light of sufficiently high frequency is incident on a metal and vacuum, the metal atoms emit electrons.
Current
Electrons liberated from the metal by the photoelectric effect will produce a net charge flow per unit time.
Threshold frequency (ft)
The minimum frequency of light that causes ejection of electrons. If the frequency of the incident photon is less than the threshold frequency (f<ft), then no electron would be ejected because the photons do not have sufficient energy to dislodge the electron from its atom. But if the frequency of the incident photon is greater than the threshold frequency (f>ft), then an electron will be ejected in the maximum kinetic energy of the ejector. Electron would be equal to the difference between hf –hft.
Energy of a photon of light.
E = hf
E = energy of the photon of light
h = the plane constant (6.62 x 10^-34 J.s)
f = the frequency of the light.
The energy of a photon increases with increasing frequency. There’s weak hold that metals have on their valence electrons due to their low ionization energies.
Maximum kinetic energy of an electron in the photoelectric effect.
Kmax = h f – W
W = Work function of the method in question. The work function is the minimum energy required to eject an electron, and it is related to the threshold by this equation:
W = h ft
K max It’s only achieved when all possible energy from the photon is transferred to the ejected electron.
Mass defect and energy.
E = mc^2
E = energy
m = mass
c = Speed of light.
The Mass defect is a result of the matter that has been converted to energy.
Nucleons
Protons and neutrons that come together to form the nucleus.
Binding energy.
Allows the nucleons to bind together in the nucleus.
What are the four fundamental forces of nature?
Electricstatic, gravitation, strong nuclear force and weak nuclear force.
Atomic number.
(Z), Usually at the bottom.
Mass number.
(A), Usually at the top.
Fusion.
Ocurs when small nuclei combine to form a large nucleus.
Fission
Process by which a large nucleus splits into smaller nuclei.
Radioactive decay.
When basing nuclear reactions to some of the atomic numbers must be the same on both sides of the equation. The sum of the mass numbers must be the same on both sides as well. Start by balancing the number of protons.
