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Atoms. What is an Atom?. The smallest particle into which an element can be divided and still be the same substance. . There are 20,000,000,000,000,000,000,000 atoms in every penny. That number is equal to twenty thousand billion billion atoms!.
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What is an Atom? • The smallest particle into which an element can be divided and still be the same substance. There are 20,000,000,000,000,000,000,000 atoms in every penny. That number is equal to twenty thousand billion billion atoms!
How many atoms are in the thickness of Aluminum Foil? This Aluminum Foil is 50,000 atoms thick.
Nucleus • The atoms center region made up of protons and neutrons.
Atom • atom
So what are atoms made of? • Proton= Positively charged= +1 • Neutron=Neutral or no charge= 0 • Electron=Negatively charged= -1
Where are Electrons found? • Electron Cloud: regions around the nucleus where electrons are likely to be found.
How did they determine the shape of the atom? • Rutherford
Mass of Atom • Measured in AMU’s: Atomic Mass Unit • Protons=1 AMU • Neutrons=1 AMU • Electrons= O AMU
Hey Everybody! Lets Draw Some Atoms! • Turn to page 794, find the element Nitrogen. • Using the periodic table, determine the number of protons, neutrons and electrons in Nitrogen.
Let’s Draw Some Atoms • Beryllium (Isotope of +1) • Lithium (Charge of +1) • Fluorine (Charge of -1)
Review on Atomic Structure • moby
Isotopes • Isotopes are atoms that have the same number of protons as normal but have different numbers of neutrons.
Atomic Mass • Is the weighted average of the masses of all the isotopes of that element.
What causes atoms to Bond? • Valence electron: an electron in the outermost energy level. • Atoms want to fill their outermost level or have a full set of valence electrons.
Electron Orbital • Closest to nucleus: Holds two electrons • Next level out: holds 8 electrons • Next level out: holds 8 electrons
Covalent Bonding • When two atoms share one or more pairs of electrons.
Covalent Bonds • Formed between non metals.
Best Friends Forever • Covalent and Ionic Bonding
Ionic Bond • When electrons are transferred from one atom to another. • This allows both atoms to have a full set of valence electrons.
Ion • An ion is formed when an atom gains or loses an electron. • Negative: when atom gains electron • Positive: when atom gives away electron
So what causes them to bond? • Opposites attract, positive and negative ions (atoms) attract to each other. • Formed between a metal and a nonmetal. • Mr. Excitement
Ionic Bonds • Form a structure called a crystal lattice, a large symmetrical, repeating , 3D pattern • Crystal Lattice
Metallic Bond • Formed by attraction between positively charged metal ions and electrons in the metal. • metallic bonding
Chemical Formula • Combination of chemical symbols and numbers to represent a substance. • H20=water
Chemical Equation • Uses chemical symbols and formulas as a shortcut to describe a chemical reaction. • Ex: 2H + O= H2O
Chemical Equation • Reactants= starting materials • Products= formed after reaction • Reactants must equal products=balanced
2H + O= H2O • Reactants = 2H, O • Product: H20
Law of Conservation of Mass • Mass cannot be created or destroyed, but changed from one form to another. • Antoine Lavoisier