Unit 3 Day 1 "Atoms" John Dalton J.J. Thomson Robert - - PDF document

Unit 3 Day 1.notebook September 24, 2015

Unit 3 Day 1 "Atoms"

John Dalton

J.J. Thomson

Robert Millikan

Rutherford's Experiment

Unit 3 Day 1.notebook September 24, 2015

Br

81 35

symbol Atomic symbols NOT!!! on a periodic table

Atomic Number:

• # of protons
• if the atom is neutral

(not an ion) then also the # of e

­

WHAT IT IS!!!!

• Mass Number:
• # protons + #

neutrons

• NOT the average

atomic mass

­1

Charge: only there if it is an ion (lost

• r gained

electrons)

Said another way:

Bromine­81

Unit 3 Day 1.notebook September 24, 2015

Br

79.91 35

symbol

Atomic Number:

Atomic symbols on a periodic table

Average atomic mass:

• average mass of

all the isotopes of the element

• (mass * %) + (mass*%)...etc

100

(27.976927 * 92.23) + (28.976495 * 4.67) + (29.973770 * 3.10) 100

=

Isotope From Wikipedia, the free encyclopedia Isotopes are variants of a particular chemical element. While all isotopes of a given element share the same number of protons, each isotope differs from the

• thers in its number of neutrons

Calculating Average Atomic Mass

Unit 3 Day 1.notebook September 24, 2015

all the same number (if not an ion) (if an ion add or subtract e

­)

• ne of these tells you the other

# p+ + #n

mass# ­ atomic #

Unit 3 Day 1.notebook September 24, 2015

periods

group number

similar properties

Name of group: Alkali earth metals (other names on pg. 124) Alkali metals Alkaline Earth metals Transition Metals Halogens Nobel or Inert gases

Unit 3 Day 1.notebook September 24, 2015

Half life calculations Nuclear Equations Nuclear Equations

Unit 3 Day 1.notebook September 24, 2015

Half life calculations

Attachments Bohratom.swf Rutherford_s Experiment_ Nuclear Atom­1.flv Cathode ray tube and electron.flv