Introduction to CHEMISTRY

1. Introduction to CHEMISTRY

2. Composition of Matter • Everything in Universe is composed of matter • Matter is anything that occupies space (has volume) and has mass

3. Everything in Universe is composed of matter. • Matter is everything around you. • Matter is anything made of • atoms and • molecules.

4. 96% of the mass of an organism is composed of • 4 elements (kinds of atoms) • Oxygen • Carbon • Hydrogen • Nitrogen

5. Each element (atom) is unique and arranged in the “Periodic Table of the Elements” is a nicely organized collection of data about the properties of the elements.

6. Atoms • Are the simplest particle of an element (matter) that retains all the properties of that element • Atoms are made of three parts.

7. The Nucleus • The NUCLEUS Consists of 2 parts • positive chargedprotons • neutralneutrons

8. and the Electrons • Negatively charged particles • Travel at very high speeds at various distances around the nucleus Protons Neutrons Electrons

9. Compounds Carbon Oxygen • Most elements do not exist by themselves • Elements combine with other elements in a predictable fashion Hydrogen

10. Compounds • A compound is a pure substance made up of atoms of two or more different elements • The ratio of atoms are always fixed for a particular compound. Chemical formulas shows the kinds and ratio of atoms of each element that occurs in a particular compound. Water = 2 Hydrogen + 1 Oxygen H2O

11. Molecules Simplest form of a substancesoftwo or more atoms held together • (a compound such as water held together by covalent bonds) that retains all of the properties of the substance Some molecules are large and complex. These are not large

12. Large Molecules in Organisms Macromolecules Nucleic Acids