Lecture 3: Earth's Internal Structure (WEEK 2) Flashcards
Planetary Differentiation
process of separating different constituents of a planetary body as a body as a consequence of their PHYSICAL and or CHEMICAL behaviour
What are the three main things for the heating of early earth
1) Accretion 2) Gravitational Pressure 3) Radioactive Decay
Accretion (for heating of early earth)
(impact collisions) cause local heating
Gravitational Pressure (for heating of early earth)
Creates pressures and temperatures high enough for melting
Radioactive decay (for heating of early earth)
by unstable isotopes
Atom
smallest division of matter that retains the characteristics of the element
-protons= positive
-electrons= negative
-neutrons= neautral
Atomic Number
= number of protons (Z)
atomic mass
= protons + neutrons
Isotopes
= elements with the same number of protons but a different number of neutrons
- same element different mass
Unstable nuclei
nuclei that spontaneously break apart (decay) to give off energy as particles or radiation
What are the most important radioactive elements heating the earth?
Uranium, Thorium, and potassium
In the melted zones within the earth what happens?
dense materials (iron-nickel) sink and light material rises
Explain what the dense material do within the core
dense iron-nickels diapir (blobs) accumulate in core taking siderophile elements (iron loving) downward
explain what the light materials do in the differentiation of early earth
lighter oxygen- seeking elements rose and solidified crust
Why was the young earth so hot?
collision and radioactive decay
