Basic Physical Principles

Lancelot L. Kao

Updated: Jan 18, 2010

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Topic

• Category of Energy

• Temperature & Heat

• Mass, Energy and Matter

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Basic Category of Energy

• Kinetic Energy– energy of motion ( K.E.= ½ mv2 ; m = mass, v

= speed )

• Potential Energy– energy being stored

• Example: Chemical energy

• Radiative Energy– energy carried by light

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Temperature Scale

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More About Kinetic Energy

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Mass, Energy, and Matter

• Definition of Mass– mass-vs-weight

• Mass-Energy Relation (Einstein 1905)– E = mc2 ; m = mass, c = speed of light

• Atomic Structure– Protons, neutrons, electrons

• Molecular Structure• States (Phases) of Matter

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Atomic Structure I

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Atomic Structure II

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Origin of Chemical Elements

• The Big Bang– All Hydrogen in the Universe– Most of the Helium

• Low Mass Stars (Stars with masses less than 4 solar masses.)– Mass loss due to stellar evolution, especially during the planetary

nebula phase– Carbon, Nitrogen, & Oxygen

• High Mass Stars– Last stage of stellar evolution which high mass stars will explode –

supernova– Heavy elements beyond Iron

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Nuclear Reactions In Stars

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Nuclear Reactions in Stars

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Planetary Nebula

MyCn 18 at 2.5 kpc

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Supernova – SN1987A

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Nuclear Binding Energy

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Molecular Structure

• Simple definition of a molecule: more than one atoms bind together to form a new chemical compound

• Basic chemical bonding mechanism– Covalent bonds– Ionic bonds– Metallic bonds– Hydrocarbon bonds

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Covalent & Ionic Bonds

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Covalent Bonds of Water

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Ionic Bonds of Sodium Chloride

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Metallic Bonds

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Hydrocarbon Bonds of Methane

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Some Organic Compound

Citric Acid

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Ring Structures

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