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Principles of Matter and Energy. Outline. I What is Matter III Types of Bonds A. Elements A. Ionic B. Compounds B. Covalent II Atoms IV Chemical Reactions A. Components B. Ions C. Isotopes D. Energy. What is Matter?.
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Outline I What is Matter III Types of Bonds A. Elements A. Ionic B. Compounds B. Covalent II Atoms IV Chemical Reactions A. Components B. Ions C. Isotopes D. Energy
What is Matter? • Matter: • Unit of matter is the atom • Matter consists of elements which are combined to form molecules and compounds
Elements • Exs: H hydrogen, O oxygen, He helium, Ca calcium, Au gold
Compounds • Molecule:
Components of Atoms • Atom:
Components of Atoms • Made up of three types of particles: • Protons: • Neutrons: • Electrons:
Ions • Usually #protons = #electrons • Atom has no net charge = neutral • Ion: • Cation: • Anion:
Isotopes • Atoms of the same element that differ in atomic mass • Examples:
Isotopes • Radioactive isotopes: nucleus decays spontaneously releasing high-energy electromagnetic radiation, subatomic particles, or both
Isotopes • Half-life: • Example: Tritium (3H) decays into 3He with a half-life of 12.5 years • Some isotopes have very short half-lives (e.g. iodine) while others are extremely long (e.g. plutonium, a waste product of nuclear power reactions, has a half-life of 24,000 years.
Isotopes • By determining ratios of the different isotopes of carbon and other elements in samples of biological origin and in rocks, scientists are able to determine with certainty when these materials formed. • Half-life cannot be changed by temperature, pressure, chemical reactions, or any other environmental factor. • Another use of isotopes is in medicine-tracking physiological processes. E.g. isotope of iodine used to check for thyroid problems
Chemical Bonding • Chemical Bond:
Ionic Bonds • Example:
Covalent Bonds • Electronegativity:
Non-polar Covalent Bonds • Examples
Polar Covalent Bonds • Examples
Hydrogen Bonds • Example
Molecular Shape and Function • Examples