Elements and Atoms • Matter is anything that has mass and takes up space. • Atoms are the basic building blocks of all matter. • Elements are basic substances that cannot be broken down into other substances. • Molecules are formed by the joining of atoms of two or more elements.(smallest combination that cannot be divided without changing its chemical and physical properties) • Compoundsare composed of atoms of different elements chemically combined.
Atoms • The center of an atom is called the nucleus. • Consists of three subatomic particles called: • Protons: positive charge • Neutrons: neutral/no charge • Electrons: negative charge • 1st level can hold 2 electrons • 2nd level can hold 8 electrons • 3rd level can hold 8 electrons
Atomic Number: Protons Symbol Element Atomic Mass Number: Protons + Neutrons Periodic Table 12 Mg Magnesium 24.305 (Nucleus) QUESTION: What part of the atom gives the atom its mass??
Protons Protons + Neutrons Periodic Table 12 Mg Magnesium 24.305 Protons = Electrons In a neutral atom
Periodic Table 12 Mg Magnesium 24.305 Protons = Electrons = Neutrons = 12 12 24-12 = 12
Bonding The sharing of electrons in order to become stable is called covalentbonding. (2 nonmetals)
Periodic Table H H O Water
Bonding + + - Water Covalent Bond
Bonding • The gaining or losing of electrons in order to become stable is called ionic bonding. ( a metal with a nonmetal) http://www.dac.neu.edu/physics/b.maheswaran/phy1121/data/ch09/anim/anim0904.htm
Bonding Sodium Chloride
Bonding + - Sodium Chloride Ionic Bond
Chemical Equations CH4 + 2O2 CO2 + 2H2O Reactants Products CO2 + H2O + LIGHT ENERGY C6H12O6 + O2 Equation for Photosynthesis 6 6 6
Inorganic Substances Not Containing Carbon • Acids: substances that forms hydrogen (H) hydrogen ions in water. pH of 0-7. • Bases: substance that forms hydroxide ions (OH) in water. pH scale of 7-14. • Salts: Inorganic substances that typically contain Chlorine. HCl NaOH NaCl H2SO4 MgCl2 KOH
Organic Substances Molecule that is found in living systems; contains carbon; usually in rings or long chains
Organic Substances • Carbohydrates: made up of simple sugars (saccharides)
Organic Carbohydrate Protein Lipid Nucleic Acid Inorganic Acid Base Salt