universal origins

universal origins - • Water originated from volcanic...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Principles of Biology Universal Origins Origins Heirarchy exists at all levels The origin of the universe o The ‘Big Bang Theory’ is the term used to describe the beginning of the universe, probably around 14 billion years ago. The universe exploded from a single point and slowly cooled. o Every element heavier than hydrogen, helium and lithium was created by stars and released into the universe. A galaxy is formed by a giant star collapsing and compacting densely. It explodes into a supernova, releasing enough heat and energy to form heavier elements. These explosions leave nebula clouds, which condense to form new solar systems. This cloud begins to spin and flatten into a disk. The center of the disk forms the sun. The rest of the disk condenses into a planet. Earth grew by the aggregation of materials. Gravity pulled all the material together. High temps in the inner core turned the earth into a semisolid mass. Dense iron fell towards the center to form the core. Density stratification is evident in the core, mantle, and the crust.
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: • Water originated from volcanic activity. They produced vapor which eventually formed clouds, and then precipitation. Elements of Life • Life made up off about 25 different chemical elements. • • Carbon, hydrogen, nitrogen and oxygen make up the bulk of things. • Atoms consist of protons, neutrons, and electrons. An atom is the smallest particle of an element that retains the element’s characteristics. o Protons are positive, neutrons are neutral, and electrons are negative. o Isotopes are elements with the same number of protons, but a different number of neutrons. o Electrons are arranged in shells, which may hold varied numbers of electrons. • Atoms whose outer shells are not filled tend to react with other atoms, by losing, gaining or sharing electrons. This forms chemical bonds. o Covalent bonding shares electrons. o Hydrogen bonds are weak, but important....
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online