ATOMIC THEORY ATOMS, THE STUFF IN STUFF

The physical universe is made of Matter and Energy Energy can take many forms but all regular matter is made of Atoms All Notes are in yellow on a blue background. The rest is extra information I want to share with you.

FIRST IDEAS OF ATOMIC THEORY (BEFORE SCIENCE) Greek In the 5th century BCE, Leucippus and his pupil Democritus proposed that all matter was composed of small indivisible particles called atoms, in order to reconcile two conflicting schools of thought on the nature of reality. On one side was Heraclitus, who believed that the nature of all existence is change. On the other side was Parmenides, who believed instead that all change is illusion. Leucippus DemocritusHeraclitus ParmenidesLeucippus DemocritusHeraclitus Parmenides

WHAT ARE ATOMS? Atoms are the basic building blocks of matter that make up everyday objects. A desk, the air, even you are made up of atoms! Maybe the greatest scientific truth ever discovered. There are 92 naturally occurring kinds of atoms. Scientists in labs have been able to make about 25 more.

PERIODIC TABLE (ALL THE TYPES OF ATOMS)

ATOMIC STRUCTURE All atoms have: Negative electrons on the outside Positive protons in the center (Nucleus)  And all but hydrogen have neutral Neutrons in the nucleus too

DALTON DISCOVERS ATOMS Around Two hundred years ago John Dalton described ELEMENTS Made of only one type of atom (all found on periodic table) Each type of Atom has a certain number of Protons carbon for example has 6 protons (H,C,O,N, Cl)

DIFFERENT ATOMS BONDED TOGETHER COMPOUNDS When,more than one type of atom is bonded Together (CO 2, H 2 O, CH 4 )

WHICH ARE COMPOUNDS AND WHICH ARE ELEMENTS?

MODERN ATOMIC THEORIES Atomic theory has progressed greatly over the last two hundred years. We now know the atom is divisible and has two main areas and three main particles

ELECTRON (NEGATIVE CHARGE FOUND ON THE OUTSIDE OF THE ATOM) Electrons – are found in shells on the outside of an atom they have a negative charge and very little mass. ( About 1/1800 th of the proton’s mass)

(PS) ELECTRONS COME IN SHELLS Valence electrons electrons found on the outermost shell. These are the same in every family Ex: Family 1 has 1 Maximum # in shells 2, 8, 18 Why can we say we never touch anything?? Where are electrons found? What charge do electrons have?

(PS) VALENCE NUMBER The valence number determines chemical reactivity (the types of reactions and bonds that can form) Elements will either gain or lose electrons to get to a stable octet (8) Elements will take the shortest steps to get to 8, ( In your own words explain ) Where does light come from?

(PS) CHEMICAL FAMILIES All vertical columns have the same number of valence electrons. Family 1 has 1 2 has 2 13 has 3 14 has 4 15 has 5 16 has 6 17 has 7 18 has 8

THE NUCLEUS The nucleus is 10,000 times smaller than the electron cloud. Almost all of the mass is found here, and it has two main parts. Protons (1 atomic mass unit (amu) & a positive charge) Neutrons (1 amu mass, no charge)

WHAT ARE ATOMS MADE OF? In the Nucleus of the Atom we have both: Protons (1 atomic mass unit (amu) & a positive charge +) Neutrons (1 amu mass, no charge) Outside of this orbit the negatively charged electron with 1/1826the mass of the proton.

PERIODIC TABLE

ATOMIC MASS & ATOMIC NUMBER Atomic number = to proton number and is the number that determines what the element is. Atomic mass is equal to the number of protons and neutrons combined

ISOTOPES Isotopes are forms of an element that have the normal number of protons, but different numbers of neutrons (If you change the proton number you change the element)

QUANTUM UNCERTAINTY

THREE QUARKS FOR MUSTER MARK (MURRAY GILLMAN TAKES A LINE FROM JAMES JOYCE’S’ “FINNEGAN’S WAKE”) Protons and Neutrons are made of even smaller Quarks Three quarks make up protons and neutrons Two “up” quarks (+2/3 each) and a down (-1/3) make a proton (+1) Two downs and an up make a neutron

QCD = Quantum Chromo Dynamics

JUST A THEORY Our understanding of atoms and atomic behavior has grown and continues to grow as our ability to measure and test (experiment with ) the smallest particles of existence has grown. Our current atomic theory is the most accurate thing humans know and its still “just a theory” In science we test our theories in every way we can.

E=MC 2 (MATTER FROM ENERGY) People have been able to create matter from energy by slamming particles together at near the speed of light. We create pressures and temperatures similar to the COSMOS a few nanoseconds after the big bang The Large Hadron Collider (LHC) is being built in a circular tunnel 27 km in circumference. The tunnel is buried around 50 to 175 m. underground. It straddles the Swiss and French borders on the outskirts of Geneva. To be completed in 2007

INCREASING FROM SMALLEST TO LARGEST WE HAVE  ATOMS, MOLECULES, CELLS, PLANETS, SOLAR SYSTEM, UNIVERSE