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Elements And Compounds. Chemistry Dr. May. Atoms. 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. 11. 12. 11. 18. 17. 17. Elements.
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Elements And Compounds Chemistry Dr. May
Atoms • 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 11 12 11 18 17 17
Elements • 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.
Elements And Atoms • 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 • 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 • 91.00% hydrogen • 8.75% helium • 0.25% others
Elements On Earth • 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 • 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)
Seven elements occur as diatomic molecules. Hydrogen (H2) Nitrogen (N2) Oxygen (O2) Fluorine (F2) Chlorine (Cl2) Bromine (Br2) Iodine (I2) Diatomic Elements
The End • This presentation was created for the benefit of our students by the Science Department at Howard High School of Technology • Please send suggestions and comments to rmay@nccvt.k12.de.us