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Transcript of Hello Minions
Hello MinionsNow for the nifty stuffHistory lesson430 BC (a long, long time ago)Greek PhilosopherDemocritusMatter is formed by small pieces that could not be cut into smaller parts.ATOMOS UncuttableATOM
History lesson continuedJump forward to the 1600sJohn Dalton (English chemist)Came up with some ideasAll elements are composed of atoms that cannot be dividedAtoms of same element are alike and have the same massDifferent elements are different and have different massesAtoms cannot be changed into another atomAtoms cannot be created or destroyed, only rearrangedEvery compound is made of atoms of different elements in set ratios
More history1897 (English scientist) J.J. ThompsonCame up with a theory of the atom being a positive ball with scattered negative charges surrounding it.Negative charges later became known as Electrons
Still more history1911 Ernest Rutherford (Thomsons student)Gold foil experimentNucleusProtons
Last bit of history1920sScientists said a cloud surrounds the nucleusNot like planets orbiting a sunElectrons movement is related to the energy level (or specific amount of energy it has)
Comparison of Particles
Were NumberEvery atom of an element has the same number of protonsCarbon has 6 protonsOxygen has 8 protonsIron has 26 protonsRadium has 88 protons!!!This unique number of protons in the nucleus of an atom is an elements ATOMIC NUMBER!
There is always an exceptionAlthough all atoms have the same number of protonsThe number of Neutrons can differ!When the number of neutrons differ from the protons, this is called an ISOTOPE.
There is always an exceptionAn isotope is identified by its MASS NUMBER which is the sum of its protons and neutrons.For example Carbon-12 (most common) (6 protons + 6 neutrons)Carbon-13 (6 protons + 7 neutrons)Carbon-14 (6 protons + 8 neutrons)