Physical Geology

1. Physical Geology Chapter 4

2. Matter • Anything that has mass and volume • Elements = simplest stable form of matter • Made of atoms • Compounds = chemically combined elements • Made of molecules • Elements:atoms::compounds:molecules

5. 98% of crust is 8 elements and their compounds

6. Atomic Structure • Small electrons in cloud (- charge) • Much larger protons in nucleus (+ charge) • Slightly larger neutrons in nucleus (0 charge) • Every element unique

7. Common units of mass, such as grams, are much too large to conveniently describe the mass of an atomic nucleus or any of its constituent parts. To solve this problem a new unit was defined: the atomic mass unit (amu). The atomic mass unit is a relative unit defined arbitrarily by assigning a mass of 12 amu to the neutral atom carbon-12, the common isotope of carbon. One atomic mass unit equals 1.66 X 10-24 grams. Employing this value, the masses of the fundamental particles of an atom have been determined to be: (1) Proton mass: 1.00727 amu. (2) Neutron mass: 1.00867 amu. (3) Electron mass: 0.00055 amu.

9. = atomic number

10. = atomic mass

11. Forms of the same element • Differ in # of neutrons • Same atomic number but different atomic mass (heavier) • Similar behavior with some different properties • Leads to average atomic mass • H = 1.00794 amu

12. Ions

13. Valence electrons create behaviors/properties and establish periodic groups on table

14. Metals have 1-3 valence electrons and lose them easily • Non-metals have 4-7 electrons and tend to gather more

16. Mendeleev’s Table

18. 2 and 8 electrons create unreactive state (Happy) Is this important?

20. How do they become “happy”?Chemical bonding!

21. Ionic bond – giving/taking e-

22. Covalent bond – sharing e-

23. Polar covalent molecule + _

24. Mixtures • Unlike a compound, the components are not chemically combined, just physically combined • Heterogenous – not equally mixed • Homogenous – “solution” and equally mixed