OCS 3103: Global Environmental Cycles

Biogeochemical Cycle

describe the flow of essential elements from the environment through the living organisms and back into the environment.

Big Bang Theory

~13.7 billion years ago
Extremely Hot (10^8K)
Atomic Nuclei were created about 3 minutes

relative abundance of hydrogen (76% and helium 24%)

Nuclear Fusion in stars; currently abundances

Hydrogen (73%)

Helium (26%)
Everything Else (1%)

Supernova

explosion of a star

Next Three Elements from Big Bang Theory and stars

Lithium (Li)
Beryllium (Be)
Boron (B)

The general trends in the remaining stellar-produced elements

(1) an alternation of abundance in elements as they have even or odd atomic numbers
(2) a general decrease in abundance, as elements become heavier

Atom

an atom is a fundamental piece of matter

three subatomic particles: protons, neutrons, and electrons

Three Subparticles

Z = protons (atomic no.), post charge
N = neutrons, neutral charge
e = electrons, negative charge
A = atomic mass = Z+N

Stability of Nucleus

Spin Pairing

Shell Binding(Orbitals)

Surface Tension

Column Repulsion

Binding Energy

reflects four processes and is the energy that would be required to dissemble the nucleus of an atom into its components parts
mass defect = change in M

Highest Binding Energy

Iron (Fe)
is STABLE, boding of nuclei is dominated by two forces - strong nuclear force and electromagnetic force.
adding or removing would result in higher-energy configuration

VERY STABLE

small nuclei, they are more likely to stick due to attraction of the strong force

NOT VERY STABLE

larger nuclei, the size of nuclei does not feel much strong force attraction form particles on the other side but they feel the elctromagnric repulsion 

Elemental Isotopes

same elect has the same number of protons (Z) but different number of neutrons

Two types of isotopes

Radioisotopes
Stable Isotopes (N/Z = 1 and 1.6)

Radiation

energy in the form of high-speed particles (or electromagnetic waves or photons) can be ionizing and non-ionizing

Mode of Decay

alpha particles:most densely ionizing, but least penetrating

beta particles: use less energetic , but more penetrating

gamma rays: high energy electromagnetic energy waves and the most penetrating types of radiation

Fission vs Fusion

Fission: breakdown into smaller
Fusion: combing

Composition of the Earth Crust

O, Si, Al, Fe, Ca, Na, K, Mg

Composition of the Earth’s core

Fe,S,Ni

Composition of the Mantle

O,Si,Mg,Fe, Al (MgSiO3 and FeMgSiO4)

composition of the human body

O,C,H,N,Ca,P,K,S,Na,Cl,Mg, I, Fe