Nuclear Chemistry, the chemistry of protons and neutrons
Names to know:
Earnest Rutherford(1899) found that alpha rays could be stopped a thin pieces of paper
Paul Villard(1900) discovered that the high energy, extremely penetrating gamma ray having characteristics of light waves
Henri Becquerel(1896) experimented with phosphorescence of certain
Madame(Marie) Curie(18591906) discovered that some elements are more radioactive than others
Radioactivity is the result of an natural change of an isotope of one element into an isotope of a different element resulting in a nuclear reaction We also discuss several other topics like What is the means by which a sender transmits a message?
Nucleons protons and neutrons
Alpha Particle Helium nuclei
Beta Particle an electron
Gamma Rays energy that can be released in the form of highly energetic photons Stability of atomic nuclei is based on relative number of protons and neutrons when a greater neutron/proton ratio exists( beta decay occurs) If you want to learn more check out Do employees have due process rights?
when a greater proton/neutron ratio exists( positron emission occurs)
for elements greater than atomic number 83( alpha emission occurs decreasing the number of protons and neutrons by 2)
Positron Emission a proton is converted to a neutron by positron emission Halflife the time required for exactly 50% of the original material to decay Application of Radioactivity:
Radio carbon dating determining the age of a sample using the carbon 14 isotope Gamma rays from cobalt60 and cesium137 are used to irradiate food
Food radiation retards the growth of organism such as molds, bacteria, and yeasts Medicine
Diagnosis radioisotopes are inserted into the patients body allowing an image to be produced of the problem area
Fissionlarge amounts of energy are released when heavy atomic nuclei split Fusion large amounts of energy are released when small atomic nuclei are combined
Octet Rule in forming bonds, maingroup elements gain, lose, or share electrons to achieve a stable electron configuration with eight valence electrons If you want to learn more check out How do you find the poh of a weak base?
Ionic Bond the attraction between positive and negative ions
Ionic compounds compound composed of positive and negative ions
Formula unit in ionic compounds, the simplest ratio of oppositely charged ions that gives an electrically neutral unit
Naming Binary Ionic Compounds
Cation= metal= common name (+)
Anion= nonmetal= name ends in ide()
Polyatomic ion a group of atoms with a net charge that behaves as a single particle Covalent Bonds
Covalent Bond a bond in which 2 atoms share electrons to achieve a noble gas configuration
Lewis Structure electron dot representation of valence electrons in a molecule( the valence electrons, represented by dots, are placed around the symbol until they are used up or until all 4 sides are occupied) Don't forget about the age old question of What two domains are prokaryotes divided into?
Bonding pair pair of electrons shared between 2 atoms in a molecule
Nonbonding pair unshared pair of valence electrons in a molecule
Electronegativity is the ability of an atom to attract electrons toward itself Multiple Covalent Bonds
Double Bond a bond in which two pairs of electrons are shared between atoms Triple Bond a bond in which three pairs of electrons are shared between atoms Polar and Nonpolar Bonding
Nonpolar describes a bond or molecule in which charge is evenly distributed, with no positive or negative regions
Polar describes a bond or molecule in which charge is unevenly distributed, creating positive and negative regions, based on differences in electronegativity
Properties of Molecular and Ionic Componds
Electrolyte compound that conducts electricity when melted or dissolved in water
Nonelectrolyte compound that does not conduct electricity when melted or dissolved in water, or does not separate into ions in water
Intermolecular forces attractive forces that act between molecules; weaker than covalent bonds DipoleDipole forces attractive forces between polar molecules
Hydrogen Bonding attraction between a hydrogen atom bonded to a highly electronegative atom (O,N,F) and an electronegative atom in another or the same molecule We also discuss several other topics like What was the explosion of diversity during the cambrian period about?
The States of Matter
Solids fixed shape and fixed volume, noncompressible, very strong intermolecular forces Liquids variable shape but fixed volume, strong intermolecular forces, noncompressible Gases variable shape and volume, compressible, weak intermolecular forces If you want to learn more check out What are three ways to reduce health care costs?
Things you need to know for the test:
∙ Symbol for the radioactive decay( beta, positron, alpha, gamma) and the formulas for each one
∙ Know the medicine isotopes name , halflife hours, and the uses ∙ Know the common ions
∙ Know all the polyatomic anions ( names and formulas)
∙ Shapes for molecules( linear, trigonal planar, tetrahedral)
∙ Naming Binary Compounds( mono, di, tri, tetra, Penta, hexa, hepta, octa, Nona, deca)