What is an atom?What is an atom?

Democritus, Greek Philosopher, 400 B.C. Democritus, Greek Philosopher, 400 B.C. Theorized that matter was made up of Theorized that matter was made up of small indivisible particles, “atomos”. He small indivisible particles, “atomos”. He theorized that these particles were infinite theorized that these particles were infinite in number, indestructible, and always in number, indestructible, and always movingmoving

Reeaallyy?Reeaallyy?

John Dalton, English dude, 1800, John Dalton, English dude, 1800, theorized that matter atoms of the same theorized that matter atoms of the same element are identical, atoms of different element are identical, atoms of different elements can combine, and chemical elements can combine, and chemical reactions occur when this happens.reactions occur when this happens.

Are you cereal?Are you cereal?

JJ Thomson, English dude, 1897, found JJ Thomson, English dude, 1897, found that atoms were not just solid spheres of that atoms were not just solid spheres of matter, they had negative charges, he matter, they had negative charges, he called electrons. His experiment used called electrons. His experiment used cathode ray tubescathode ray tubes

Robert Milikan, American (Yea baby) Robert Milikan, American (Yea baby) shortly after Thomson found the amount of shortly after Thomson found the amount of the electrons charge, oil drop experimentthe electrons charge, oil drop experiment

Veeerrryyyy interesting.Veeerrryyyy interesting.

Eugen Goldstein, discovered that atoms Eugen Goldstein, discovered that atoms had positive chargeshad positive charges

James Chadwick, discovered that atoms James Chadwick, discovered that atoms had neutronshad neutrons

Ernest Rutherford, English dude (again), Ernest Rutherford, English dude (again), 1911, discovered that atoms had a small 1911, discovered that atoms had a small dense core of protons and neutrons and dense core of protons and neutrons and were composed mostly of empty spacewere composed mostly of empty space

I am so excited.I am so excited.

Neils Bohr, German guy, 1913 developed Neils Bohr, German guy, 1913 developed what is called the “planetary model”, electrons what is called the “planetary model”, electrons orbit in specific paths around the nucleus.orbit in specific paths around the nucleus.

Louis de Broglie and Erwin Scrhodinger Louis de Broglie and Erwin Scrhodinger develop the idea that electrons have develop the idea that electrons have properties of waves and matter and travel properties of waves and matter and travel around the nucleus in areas, not paths, called around the nucleus in areas, not paths, called the electron cloud model, also called the the electron cloud model, also called the quantum mechanical model.quantum mechanical model.

AtomsAtoms

Proton, + charge, 1 amuProton, + charge, 1 amuNeutron, 0 charge, 1 amuNeutron, 0 charge, 1 amuElectron, - charge, 0 amuElectron, - charge, 0 amu

AMU = atomic mass unitAMU = atomic mass unit

Smaller units called quarks make up Smaller units called quarks make up protons and neutronsprotons and neutrons

Atomic StructureAtomic Structure

There are 4 main energy levels around an There are 4 main energy levels around an atom where electrons are found. They are atom where electrons are found. They are divided into sublevels called orbitals, each divided into sublevels called orbitals, each orbital holds 2 electrons.orbital holds 2 electrons.

S = 1 orbital = 2 electronsS = 1 orbital = 2 electronsP = 3 orbitals = 6 electronsP = 3 orbitals = 6 electronsD = 5 orbitals = 10 electronsD = 5 orbitals = 10 electronsF = 7 orbitals = 14 electronsF = 7 orbitals = 14 electrons

Atomic StructureAtomic Structure

11stst energy level = s = 2 electrons energy level = s = 2 electrons22ndnd energy level = sp = 8 electrons energy level = sp = 8 electrons33rdrd energy level = spd = 18 electrons energy level = spd = 18 electrons44thth energy level = spdf = 32 electrons energy level = spdf = 32 electrons

OrbitalsOrbitals

New, each orbital has a different shape, s New, each orbital has a different shape, s orbitals are round, p orbitals look like the orbitals are round, p orbitals look like the figure 8 on the x, y, and z axis. D orbitals figure 8 on the x, y, and z axis. D orbitals look like 2 figure eights on two axis look like 2 figure eights on two axis simultaneously, f orbitals relatively simultaneously, f orbitals relatively complexcomplex

We thought you wuz a toad!We thought you wuz a toad!

All elements emit quanta of energy as All elements emit quanta of energy as electrons move from one energy level to electrons move from one energy level to another. another.

When they become excited they move to a When they become excited they move to a higher energy level, and as they cool down higher energy level, and as they cool down the electrons fall back to their ground state the electrons fall back to their ground state emitting energy in the form of light.emitting energy in the form of light.

Do not seek the treasure!Do not seek the treasure!

Light is part of the electromagnetic spectrum. Light is part of the electromagnetic spectrum. This includes Radio waves and radar on the low This includes Radio waves and radar on the low side and x-rays and gamma on the high sideside and x-rays and gamma on the high side

Amplitude is the height of a wave from rest to Amplitude is the height of a wave from rest to crest, it is the energy in the wave.crest, it is the energy in the wave.

Wavelength, distance of a complete wave cycle, Wavelength, distance of a complete wave cycle, represented by lambdarepresented by lambda

Frequency, wave cycles per unit of time, Frequency, wave cycles per unit of time, measured in hertz, 1 wave cycle per secondmeasured in hertz, 1 wave cycle per second

That’s my boat!That’s my boat!

The wavelength and frequency are The wavelength and frequency are inversely proportional to each other.inversely proportional to each other.

Light is part of the electromagnetic Light is part of the electromagnetic spectrum, ROYGBIV, red, orange, yellow, spectrum, ROYGBIV, red, orange, yellow, green, blue, indigo, and violet, green, blue, indigo, and violet,

Red has the lowest frequency and longest Red has the lowest frequency and longest wavelength, violet has the highest freq and wavelength, violet has the highest freq and shortest wavelength.shortest wavelength.

Is that low fat milk you’re drinking?Is that low fat milk you’re drinking?

Atomic spectra is the frequency of light emitted Atomic spectra is the frequency of light emitted when the electrons in an atom fall back to their when the electrons in an atom fall back to their ground state, they actually don’t fall back they ground state, they actually don’t fall back they fall outward.fall outward.

Each element has an atomic emission spectrum, Each element has an atomic emission spectrum, or specific frequency of light emitted.or specific frequency of light emitted.

The light emitted by an electron has frequency The light emitted by an electron has frequency directly proportional to the energy change of the directly proportional to the energy change of the electronelectron

No one really knows, it just No one really knows, it just provocative!provocative!

Quanta of light are called photons, they Quanta of light are called photons, they behave as a particle and a wavebehave as a particle and a wave

This was theorized and proven by Broglie This was theorized and proven by Broglie and Schrodinger.and Schrodinger.

Due to this phenomenon, the position of Due to this phenomenon, the position of and electron is never actually known.and electron is never actually known.

Heisenberg uncertainty principle.Heisenberg uncertainty principle.

Atomic TermsAtomic Terms

Element, matter made up of all the same Element, matter made up of all the same atomsatoms

Mass Number, sum of protons and Mass Number, sum of protons and neutrons in the atomneutrons in the atom

Atomic Number, number of protons, Atomic Number, number of protons, always a whole numberalways a whole number

Atomic Mass Number, the average of all Atomic Mass Number, the average of all the isotopes of an elementthe isotopes of an element

Atomic StuffAtomic Stuff

Four Fundamental Forces that work in an Four Fundamental Forces that work in an atom.atom.

1.) Electromagnetic Force, keeps electrons 1.) Electromagnetic Force, keeps electrons around the nucleusaround the nucleus

2.) Strong force, holds the nucleus together2.) Strong force, holds the nucleus together

3.) Weak Force, radioactivity, 3.) Weak Force, radioactivity,

4.) Gravity, responsible for atomic 4.) Gravity, responsible for atomic interactionsinteractions

More Atomic Terms!!More Atomic Terms!!

Isotope, atoms of the same element with a Isotope, atoms of the same element with a different number of neutrons, usually different number of neutrons, usually radioactive. radioactive.

Substance, matter that has the same Substance, matter that has the same properties throughout, could be an properties throughout, could be an element or compound.element or compound.

Compound, substance made up of two or Compound, substance made up of two or more elements. Formulas are used to more elements. Formulas are used to represent compounds, Hrepresent compounds, H22O, COO, CO22

Periodic TablePeriodic Table

Created by Dimitri Mendeleev, Russian, Created by Dimitri Mendeleev, Russian, 1869, he organized atoms according to 1869, he organized atoms according to their atomic weighttheir atomic weight

Henry Moseley, British, 1914, rearranged Henry Moseley, British, 1914, rearranged the table by atomic number, currently used the table by atomic number, currently used today.today.

Groups or families, each vertical column, Groups or families, each vertical column, they have similar properties and the same they have similar properties and the same number of valence or outer electronsnumber of valence or outer electrons

More !?!?More !?!?

Periods or rows, horizontal rows in the table, Periods or rows, horizontal rows in the table, each row has the same number of energy levelseach row has the same number of energy levels

Each chemical is represented by the first or first Each chemical is represented by the first or first two letters in the elements name, the first letter two letters in the elements name, the first letter is always capitalized.is always capitalized.

Alkali Metals, 1Alkali Metals, 1stst column, very reactive metals column, very reactive metals Alkali Earth Metals, 2Alkali Earth Metals, 2ndnd Column, not quite as Column, not quite as

reactive metalsreactive metals

More and More!?!?More and More!?!?

Transition Elements, columns 3-12, typical Transition Elements, columns 3-12, typical metals, iron, copper, etc.metals, iron, copper, etc.

Metals, all the elements to the left of the Metals, all the elements to the left of the metalloids, conduct heat & electricity, metalloids, conduct heat & electricity, shiny, malleable (beaten and formed), shiny, malleable (beaten and formed), ductile (drawn into wires)ductile (drawn into wires)

Metalloids, diagonal column of elements Metalloids, diagonal column of elements between metals and nonmetals, they have between metals and nonmetals, they have metallic and nonmetallic propertiesmetallic and nonmetallic properties

Still moreStill more

Halogens, second to last column of Halogens, second to last column of elements, group 17, very reactive gases, elements, group 17, very reactive gases, halogen means “salt former” reacts with halogen means “salt former” reacts with metals to form saltsmetals to form salts

Noble Gases, last column, unreactive, Noble Gases, last column, unreactive, inert gasesinert gases

Nonmetals, all elements to the right of the Nonmetals, all elements to the right of the metalloids, do not conduce heat or metalloids, do not conduce heat or electricity, dull, brittle, powdery.electricity, dull, brittle, powdery.

The endThe end

Rare Earth Elements, two separate rows Rare Earth Elements, two separate rows at the bottom of the table, called at the bottom of the table, called lanthanides and actinides, all the actinides lanthanides and actinides, all the actinides are radioactive.are radioactive.