Atoms What is an atom? cale/ cale/ How did we discover the.

Atoms

• What is an atom?• http://learn.genetics.utah.edu/content/cells/s

cale/

• How did we discover the atom?• What do we already know about it?

History of the Atom

• Democritus• Dalton• JJ Thompson• Rutherford• Bohr• Other Scientists

Group Presentations

• 3 minutes to get with group

• Research the assigned scientist and their contribution to our knowledge of the atom

• Fill out the table about your scientist• Make a poster representing that information• 20 minutes – present to class

• Short Cartoon about History of Atom• TED Ed Talk on Size of the Atom

Thompson

• Veritasium: Thompson's Cathode Ray Experiment

Rutherford

• Rutherford Gold Foil Experiment Animation

Jan. 14 Warm Up

• In labbooks, answer the following questions:1. Who was the first to think of a particle so small it could

not be divided anymore? DEMOCRITUS2. Who discovered protons? RUTHERFORD3. Who used a glass tubing to find electrons? THOMPSON4. What does Bohr’s model most closely represent?

PLANETARY MODEL

Review

• Crash Course Video: History of the Atom

So how far have we come?

Bohr Model – Model to describe atom

Arrangement of Atoms

• 100+ atoms, how do we organize them?• How could we organize them?

Interactive Periodic Tables

• http://www.rsc.org/periodic-table• http://www.ptable.com/

Reading Element Square

--------------------------------atomic number (Z); # of protons

--------------------------------atom symbol

--------------------------------atomic mass (# of P + # of N)

Atomic NumberAtomic number (Z) of an element is the number of protons in the nucleus of each atom of that element.

Element # of protons Atomic # (Z)

Carbon 6 6

Phosphorus 15 15

Gold 79 79

Mass Number

Mass number is the number of protons and neutrons in the nucleus of an isotope.

Mass # = p+ + n0

Drawing the Atom

Practice

• Which element has 4 protons?• Which element has a mass of 65 amu?• Which element has the symbol Ag?• Give an example of an element that has a full

energy shell• How many electrons does N have?• How many neutrons does Ca have?

Practice Drawing Atoms

• H• He• Li• Be• B• C

• N• O• F• Ne• Na