Architecture of the Universe The size of a person is used as a reference

Small Scale Structure Elementary Particles (Quarks, Electrons) Composite Particles (Protons, Neutrons) Atomic Nuclei (Chemical Elements) Atoms and Ions Molecules

Large Scale Structure Solar System Solar Neighborhood Galaxy (Milky Way) Galaxy Cluster / Group Supercluster

Universe

ELEMENTARY PARTICLES Smallest particles in nature

- make up everything in the universe

Particle accelerators

CERN (France, Switzerland)

Particle Trails

12 Elementary Particles in nature

- have no internal structure

- have no intrinsic size

Measurable Properties:

- Mass: “quantity of matter” - not the same as weight or size

- Electric Charge: (positive or negative)

Only three are important for “normal” matter Up Quark, Down Quark, Electron

Other important particles (inside stars) Neutrino (three types)

Name

Structure

Mass*

Charge*

Up Quark

none

1/3

+ 2/3

Down Quark

none

1/3

- 1/3

Electron

none

0.0005

-1

* - atomic units * 1 amu = 1.67 x 10-27 kg

COMPOSITE PARTICLES (“HADRONS”)

Formed from groups of three quarks

* atomic units

Name Structure Mass* Electric Charge*

Proton (p or 1H)

u u

d

1.0

+1.0

Neutron ( n )

d d

u

1.0021

0

CHEMICAL ELEMENTS (Nucleus)

Formed from Protons and Neutrons

Name

Structure

Mass*

(A)

Electric

charge (Z)

Hydrogen (1H)

p

1 +1

Helium (4He)

p p

n n

4 +2

Carbon (12C)

p p p p p p

n n n n n n

12 +6

Total Charge of Nucleus (“atomic number”)

- total number of protons in nucleus

-uniquely defines an element

For example: any nucleus with 6 protons is Carbon

6p + 6n 12C (most common form)

6p + 7n 13C 6p + 8n 14C

12C, 13C, 14C are isotopes of Carbon

Symbols (Writing/Print) (Periodic Table only)

Atomic Mass (A) (Z)

X X Atomic Number (Z) * (A)

(* often omitted)

Link to Periodic Table: http://science.widener.edu/~svanbram/ptable_6.pdf

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Example: Iron 56Fe Fe 56

ATOMS AND IONS Formed from a nucleus and electrons

Name Structure Mass Charge

Hydrogen Atom (H)

1 0

Helium Atom (He)

4 0

Helium Ion (He+)

4 +1

Ion: Total charge (nucleus + electrons) 0

MOLECULES

Formed from atoms and ions. Very rare

- need lots of atoms/ions close together - need low temperatures

- less than ~3000 K (~5000oF)

Name Structure Mass Charge

Oxygen molecule (O2)

O O 32 0

Water (H2O)

O

H H 18 0

Ethanol (C2H6O)

H H

H C C O H

H H

46 0

MOLECULES

Our World

Forces of Nature

Force - describes how objects interact -objects can only attract or repel each other

- account for structure in the universe on all scales

Four Fundamental Forces

Gravitational Force

Electromagnetic Force

Strong (Nuclear) Force

Weak (Nuclear) Force

1. Gravitational Force (1685)

- only attractive

- affects all types of particles

- infinite range

- the weakest of the four forces

- dominates all large scale structure

2. Electromagnetic (EM) Force (1865)

- attractive or repulsive

- only affects particles with an electric charge

- infinite range

- stronger than gravitational force - second strongest overall

- dominates from atomic to human

3. Strong (Nuclear) Force (1935)

- attractive

- affects quarks (and composite particles) but not electrons

- short range

- strongest force

- dominates over smallest size scales up to the atomic nucleus

4. Weak (Nuclear) Force (1956)

- changes one elementary particle into another

- explains radioactivity

- affects all types of particles

- very short range

Uranium or “Vaseline” Glassware http://www.ebay.com/sch/Vaseline-/4935/i.html

Dominant Forces on All Scales

Structure

Dominant Force

Elementary Particles

Composite Particles

Strong (Nuclear) orce

Atomic Nuclei

Atoms and Ions Electromagnetic

Molecules Solar System

Gravitational Force

Solar Neighborhood

Milky Way Galaxy

Gravitational Force

The Local Group

The Local (Virgo) Supercluster

The Entire Universe