Transcript Elements And Compounds

Elements And Compounds
Chemistry
Dr. May
Atoms
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An atom is the smallest part of an
element that still has the properties of
that element.
An atom is made up of protons,
neutrons, and electrons
Atomic Inventory
Element
23
Na
11
35
17
Cl
Protons
Neutrons
Electrons
11
12
11
17
18
17
Elements
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The 88 naturally occurring elements are
the “chemical alphabet” of all
substances in the universe.
Elements can not be broken down by
chemical or physical means to simpler
substances.
Compounds And Elements
Compound
Molecule
Two or more elements
Atoms
Na and Cl
Table Salt
NaCl
Na and Cl
Elements And Atoms
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An atom is the smallest part of an
element that can enter into a chemical
reaction.
22.98977 grams of sodium contains
6.02 x 1023 atoms of sodium
Compounds and Molecules
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The molecule is the smallest part of a
compound that still has the properties
of that compound.
58.44 grams of NaCl (sodium chloride)
contains 6.02 x 1023 molecules of NaCl
Elements in Galaxies
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91.00% hydrogen
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8.75% helium
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0.25% others
Elements On Earth
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49.2% oxygen (H2O, O2, CO2)
25.7% silicon (SiO2, silicates)
7.5% aluminum (Al2O3, minerals)
4.7% iron (Fe2O3, earth’s core)
3.4% calcium (CaCO3)
2.6% sodium (NaCl, Na2CO3)
2.4% potassium (KCl, K2CO3)
Elements In The Earth’s Crust
Earth Crust
Elements In The Human Body
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65% Oxygen (H2O, protein)
18% carbon (RNA, DNA, protein)
10% hydrogen (H2O, protein, fat)
3% nitrogen (protein, DNA)
2% calcium (bones)
1% phosphorus (phosphate in DNA)
Diatomic Elements
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Seven elements
occur as diatomic
molecules.
Hydrogen (H2)
Nitrogen (N2)
Oxygen (O2)
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Fluorine (F2)
Chlorine (Cl2)
Bromine (Br2)
Iodine (I2)
The End
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This presentation was created for the
benefit of our students by the Science
Department at Howard High School of
Technology
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