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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