2. Elements And Compounds Integrated Science Dr. May

3. 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

4. Atomic Inventory ElementProtonsNeutronsElectrons 23 Na 11 35 Cl 17 111211 17 1817

5. 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.

6. Compounds And Elements

7. 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 10 23 atoms of sodium

8. 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 10 23 molecules of NaCl

9. Elements in Galaxies 91.00% hydrogen 8.75% helium 0.25% others

10. Elements On Earth 49.2% oxygen (H 2 O, O 2, CO 2 ) 25.7% silicon (SiO 2, silicates) 7.5% aluminum (Al 2 O 3, minerals) 4.7% iron (Fe 2 O 3, earth’s core) 3.4% calcium (CaCO 3 ) 2.6% sodium (NaCl, Na 2 CO 3 ) 2.4% potassium (KCl, K 2 CO 3 )

11. Earth Crust Elements In The Earth’s Crust

12. Elements In The Human Body 65% Oxygen (H 2 O, protein) 18% carbon (RNA, DNA, protein) 10% hydrogen (H 2 O, protein, fat) 3% nitrogen (protein, DNA) 2% calcium (bones) 1% phosphorus (phosphate in DNA)

13. Diatomic Elements Seven elements occur as diatomic molecules. Hydrogen (H 2 ) Nitrogen (N 2 ) Oxygen (O 2 ) Fluorine (F 2 ) Chlorine (Cl 2 ) Bromine (Br 2 ) Iodine (I 2 )

14. 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