CHEM 110 Lecture Notes - Lecture 2: Atomic Number, Unified Atomic Mass Unit

• School: PSU
• Department: Chemistry
• Course: CHEM 110
• Professor: Schmid

Document Summary

Anion= negative charge (abundance of e ) . Cation= positive charge (lack of e ) . Isotopes- atoms with the same atomic number but different number of neutrons (the. 1 number of protons is fixed, but the number of neutrons can vary) We define atomic mass of c= exactly 12 amu (contains 6 p and 6 n ; each are exactly. Use isotopic ratios to find average atomic masses. No one can see (or weigh an atom) the mole is the connection. 1 mole of anything= avagadro"s number of them (6. 02x10 ) Mole- the connection between microscopic (atoms) and macroscopic (what we see) 1 mole of c/atomic weight of c= 12. 011 g/mol. Atom diameter= 0. 1 0. 5nm ~ 10 m . Nuclear diameter= 10 nm = 10 m.