Download Outline Notes Worksheet - Ms. Blake

Name:________________________
Date:_________________________
Period:________________________
Atomic Theory
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Democritus
o Recognized that matter was made up of tiny __________________ (More
Philosophy and not actual Science)
 ATOMS!!!!!!! (Atomos=___________________)
 6th-2nd Century BC
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Dalton’s Theory (Early 1800’s)
o Dalton’s Atomic Theory
 Elements are made of very small particles called _______________.
 Atoms of a specific element are __________________ in size, mass, and
properties
 Atoms of different elements differ in size, mass, and properties.
 Atoms cannot be broken down
 Atoms of different elements ______________ in simple whole-number
ratios to form chemical compounds.
 He thought water was HO instead of H2O
 In chemical reactions, atoms are combined, ___________________, or
rearranged.
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Dalton’s Billiard Ball Model
o Atoms are solid, unbreakable, and impenetrable units of matter
 Much like a Billiard ball
 At this time in history, protons, neutrons, and electrons were not
yet __________________
 People began to think about the shape and composition of atoms
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JJ Thompson’s Theory
o 1897 discovered the _______________
 He named these particles “__________________” and they would later be
renamed electrons
o Thought corpuscles were the building blocks of matter (Atoms could be broken
down)
o Plum Pudding Model
 Corpuscles _________________________ placed
 Surrounding area (+)
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Rutherford’s Theory
o 1909 disproved Thompson’s theory
o Most of an atoms mass and positive charge is in the _______________ (Nucleus)
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o Planetary Model
 Cloud of electrons orbit a compact, positively charged nucleus
Bohr’s Theory
o 1913 An electron can only orbit the nucleus in a specific ________________
pattern (orbit)
o Bohr Model
 Each electron has a _________________ energy
 Its distance from the nucleus shows how much energy it has.
 Electrons can “jump” to a higher ________________ when energy
is added. Or move back to their original orbital. (Emits light or
gives off heat)
Protons and Neutrons
o 1917 Rutherford discovered Protons through ____________________ alpha
particles at Nitrogen.
 Hydrogen nuclei were seen after the particles hit (Hydrogen is 1 proton)
 He discovered he had __________________ an atom
 He also speculated that there must be another particle in the nucleus
 He knew an atom’s nucleus had more mass than just the
______________ of protons.
Schrodinger & Born
o Schrodinger 1926
 The movement of an electron is more like a ___________________ and
less like a particle
o Born 1926
 This wave better explains the electrons states
 Could be used to _____________________ the location of an electron
orbiting the nucleus
Heisenberg
o 1927 _________________________- Principle
 Electrons do not have a perfectly neat and circular orbit (Bohr)
 However, electrons do exist more frequently in certain areas around the
nucleus
 Called Atomic _____________________
 Based on energy level
 Many different shapes
Current Atomic Theory
o Elements are made of extremely small particles called atoms.
o Atoms of a specific element are identical in size, mass, and properties
 Atoms of different elements differ in size, mass, and properties.
o Atoms can be broken down into __________________________ particles called
 Protons
 ___________________________
 Electrons
o Atoms can combine in different _______________ through chemical reactions to
form molecules
 In chemical reactions, atoms are combined, separated, or rearranged.