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Transition Electron Micrograph (TEM)

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Presentation on theme: "Transition Electron Micrograph (TEM)"— Presentation transcript:

1 Transition Electron Micrograph (TEM)
Chemistry Basics Transition Electron Micrograph (TEM) of atoms Oxygen (O)

2 All matter is made of chemical _______
ATOMS AND MOLECULES All matter is made of chemical _______ Can’t be broken down by _________ means __ occur in nature, ~__ more in labs 8 make up 99% of the stuff on Earth’s surface __ are essential to life Organisms are made mostly (95%) of 4: Oxygen (O) Carbon (C) Hydrogen (H) Nitrogen (N) Where is each commonly encountered?

3 Periodic table of the elements
Arranged according to number of protons (more later) = ____________ Number Metals Non-metals Alkali metals

4 Each element is a kind of atom
Bohr atom, after Niels Bohr Electrons: (-) charge Nucleus Protons: (+) charge Neutrons: (+) charge

5 Electrons occur in _______ or shells
Inner shell (Oxygen) Outer shell Opposite charges _______ electrons to protons Pulls electrons toward nucleus Like charges ______ electrons from other electrons Keeps electrons spread out Electromagnetic repulsion among protons is overwhelmed by poorly-understood __________ Binds protons and neutrons Involves quarks and ______ __________ of neutrons and protons

6 Larger atoms have more ______
Each orbital has it’s maximum number of electrons 1st orbital holds 2 e- 2nd holds 8 e- Electrons in outer orbitals have ____ energy When electrons move to inner orbitals they _______ energy more energy Organisms use this to get ______ from chemical reactions

7 Atoms have electrically charged forms, called _____
The number of electrons(-) & protons(+) are ______ Negatively charged ion = anion Positively charged Ion = cation

8 Atoms can rob electrons from other atoms
Atoms with many e-s in their outer orbital rob from atoms with few e-s in their outer orbital An Oxygen atom, with 7 out of 8 e-s in its outer orbital, can rob the single e- of a Hydrogen atom Resulting in 2 ions:

9 Chemical reactions = _____ Elements combine to form _________
Hydrogen (H) plus Oxygen (O) = _____ Sodium (Na) plus Chlorine (Cl) = _____ Compounds are held together by chemical _____

10 2 major categories of compounds
1. Inorganic compounds From _________ sources Have _____ bonds Ions with opposite charges are attracted cation anion Ionic bond

11 Table salt is inorganic
Ionic bonds result in stacked blocks Form brittle ________

12 2. Organic compounds (more next lecture)
From _____ sources Have _______ bonds Atoms ______ a pair of electrons Hydrogen lacks a neutron - unique to Hydrogen Covalent bonds are strong, ______


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