Download I. Structure of the Atom

1
Chapter 2:
Atoms Are Amazing!
The Boy and His Atom
I.
Structure of the Atom
A) Early Discoveries
B) Current Model of the Atom
C) Elemental Notation
D) Atomic Mass
II.
Organization of the Elements:
The Periodic Table
III.
Quantifying Atoms
Haiku Inspired by the Atom
Sparkling crisp ocean,
Waves flickering beckoning.
Dalton’s spheres sharing.
http://www.lowpressure.co.uk/surftravelplanner/images/San%20Diego%20County%20-%20Cardiff%20to%20Blacks.jpg,
https://upload.wikimedia.org/wikipedia/en/3/37/A_Boy_and_His_Atom_(still).jpg
2
I. Structure of the Atom
What is matter composed of?
Atoms – electrons, protons, neutrons (nucleus)
A. Early Discoveries and Conclusions
Lavoisier (1774)
Law of conservation of mass -
Proust (1799)
Law of constant composition (or definite proportions)
-
https://upload.wikimedia.org/wikipedia/commons/8/8a/Proust_joseph.jpg,
https://upload.wikimedia.org/wikipedia/commons/thumb/6/6c/Antoine_lavoisier_color.jpg/220px-Antoine_lavoisier_color.jpg
3
Dalton (1803-1808)
Atomic Theory -1.
2.
3.
Thomson (1897)
-
-
https://thedamnveggies.files.wordpress.com/2012/05/road-house-01-4.jpg,
http://a5.files.biography.com/image/upload/c_fit,cs_srgb,dpr_1.0,h_1200,q_80,w_1200/MTE1ODA0OTcxNTk5OTU1NDY5.jpg, http://sardonicsalad.com, http://media2.web.britannica.com/eb-media/85/101085-004-E1192912.jpg
4
Rutherford
First Discovery (1899)
-
Second Discovery (1909)
Probe the inner structure of the atom
Gold Foil Experiment
Expectation
Alpha Particles
Conclusions -
Later
-
https://upload.wikimedia.org/wikipedia/commons/d/d1/Ernest_Rutherford_1905.jpg
Outcome
5
B. Current Model of the Atom
1. Atoms are spherical and contain electrons, protons,
and neutrons
protons (p) -
neutrons (n) -
electrons (e-)
-
2. Mass of atom and the positive charge is located in
central portion of the atom (nucleus)
Nucleus
9.9 cm
Atom
9.9 km
https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcSQiTn6gWas45GkrTlI05-U-8oA1xrRFIz0bSyAVCGb5gHgIZ3sQw, https://i.ytimg.com/vi/pzaQjS1JstY/maxresde
6
3. The identity of an atom is given by the
number of protons
4. Neutral atom
5. Atom is mostly empty space
7
C. Elemental Notation
Mass # =
Atomic # =
Charge =
Isotopes
8
Isotopes of Oxygen
Origin of the Moon
http://www.telegraph.co.uk/news/science/space/12129549/Earth-is-actually-two-planets-scientists-conclude.html, http://www.sciencemag.org/
9
EXAMPLES
1. How many protons, neutrons, and
electrons do the following elements
contain?
A.
28
14
Si
B.
85
37
Rb

C.
16
8
O 2
10
D. Atomic Mass (Weight)
Mass of atom = mass of p + mass of n + mass of e- ?
New Unit - Atomic Mass Units (AMU)
12
6
C mass = 1.3x10
-23
g
Definition of atomic mass unit -
11
Example Boron
Naturally Occuring Boron -
19.9 % 10B (mass = 10.0129370 amu)
80.1% 11B (mass = 11.0093055 amu)
Avg mass of B = 199atoms *10.0129370 amu/atom + 801atoms*11.0093055 amu/atom
1000 atoms
Avg mass of B = 10.8¦11 amu / atom
12
II. Organization of the Elements
Periodic Table
- Elements listed in sequential order by number of
protons
A) Arrangement
i.) Metals, Non-Metals, Metalloids ii.) Groups
i.) Metals
iii.) Periods
13
Nonmetals
Metalloids
14
ii.) Groups
iii.) Periods