Meriwether Lewis

Examples of Meriwether Lewis in the following topics:

• The Lewis and Clark Expedition

  • After the purchase of the Louisiana Territory, Thomas Jefferson sent Lewis and Clark to lead an expedition called the "Corps of Discovery."
  • Thus, in 1804, he commissioned his personal secretary, Meriwether Lewis, to join frontiersman and soldier Captain William Clark in recruiting a "Corps of Discovery."
  • Lewis and Clark were thus instructed to map the territory through which they would pass and to explore all tributaries of the Missouri River.
  • Having gathered woodsmen from across the country for the expedition, Lewis and Clark set out from St.
  • Upon their return, Meriwether Lewis was named governor of the Louisiana Territory.

• Conclusion: Early Trials

  • In 1803, President Jefferson authorized a "Corps of Discovery," headed by Meriwether Lewis and William Clark, to explore a passage to the Pacific Ocean.
  • The Louisiana Purchase and the journey of Lewis and Clark captured the imagination of many who dedicated themselves to the economic exploitation of the western lands and the expansion of American influence and power.

• Lewis Acid and Base Molecules

  • Lewis bases are electron-pair donors, whereas Lewis acids are electron-pair acceptors.
  • A Lewis acid is defined as an electron-pair acceptor, whereas a Lewis base is an electron-pair donor.
  • A Lewis base, therefore, is any species that donates a pair of electrons to a Lewis acid.
  • Under the Lewis definition, hydroxide acts as the Lewis base, donating its electron pair to H+.
  • We first look at the Bronsted-Lowry theory, and then describe Lewis acids and bases according to the Lewis Theory.

• Metal Cations that Act as Lewis Acids

  • Transition metals can act as Lewis acids by accepting electron pairs from donor Lewis bases to form complex ions.
  • The modern-day definition of a Lewis acid, as given by IUPAC, is a molecular entity—and corresponding chemical species—that is an electron-pair acceptor and therefore able to react with a Lewis base to form a Lewis adduct; this is accomplished by sharing the electron pair furnished by the Lewis base.
  • However, metal ions such as Na+, Mg2+, and Ce3+ often form Lewis adducts upon reacting with a Lewis base.
  • Ligands create a complex when forming coordinate bonds with transition metals ions; the transition metal ion acts as a Lewis acid, and the ligand acts as a Lewis base.
  • Usually, metal complexes can only serve as Lewis acids after dissociating from a more weakly bound Lewis base, often water.

• Lewis Structures for Polyatomic Ions

  • The Lewis structure of an ion is placed in brackets and its charge is written as a superscript outside of the brackets, on the upper right.
  • The total number of electrons represented in a Lewis structure is equal to the sum of the numbers of valence electrons in each individual atom.
  • Non-valence electrons are not represented in Lewis structures.
  • Lewis structures for polyatomic ions are drawn by the same methods that we have already learned.
  • When counting electrons, negative ions should have extra electrons placed in their Lewis structures; positive ions should have fewer electrons than an uncharged molecule.

• Formal Charge and Lewis Structure

  • In particular, chemists use Lewis structures (also known as Lewis dot diagrams, electron dot diagrams, or electron structures) to represent covalent compounds.
  • Non-valence electrons are not represented when drawing the Lewis structures.
  • In the Lewis structure, carbon should be double-bonded to both oxygen atoms.
  • Lewis structures can also be drawn for ions.
  • Sometimes multiple Lewis structures can be drawn to represent the same compound.

• Representing Valence Electrons in Lewis Symbols

  • Lewis symbols use dots to visually represent the valence electrons of an atom.
  • Lewis symbols (also known as Lewis dot diagrams or electron dot diagrams) are diagrams that represent the valence electrons of an atom.
  • Lewis structures (also known as Lewis dot structures or electron dot structures) are diagrams that represent the valence electrons of atoms within a molecule.
  • These Lewis symbols and Lewis structures help visualize the valence electrons of atoms and molecules, whether they exist as lone pairs or within bonds.
  • Lewis symbols for atoms are combined to write Lewis structures for compounds or molecules with bonds between atoms.

• Introduction to Lewis Structures for Covalent Molecules

  • The Lewis formalism used for the H2 molecule is H:H or H—H.
  • The resulting molecule that is formed is F2, and its Lewis structure is F—F.
  • We have looked at how to determine Lewis structures for simple molecules.
  • The Lewis structure for carbon dioxide, CO2, is a good example of this.
  • Predict and draw the Lewis structure of simple covalent molecules and compounds

• Writing Lewis Symbols for Atoms

  • The Lewis symbol for an atom depicts its valence electrons as dots around the symbol for the element.
  • In order to write the Lewis symbol for an atom, you must first determine the number of valence electrons for that element.
  • Lewis symbols for the elements depict the number of valence electrons as dots.
  • Once you can draw a Lewis symbol for an atom, you can use the knowledge of Lewis symbols to create Lewis structures for molecules.
  • In the Lewis symbol, the electrons are depicted as two lone pair dots.

• Physical Properties of Covalent Molecules

  • First described by Gilbert Lewis, a covalent bond occurs when electrons of different atoms are shared between the two atoms.
  • The Lewis bonding theory can explain many properties of compounds.
  • Lewis bonding theory states that these atoms will share their valence electrons, effectively allowing each atom to create its own octet.
  • Lewis theory also accounts for bond length; the stronger the bond and the more electrons shared, the shorter the bond length is.
  • However, the Lewis theory of covalent bonding does not account for some observations of compounds in nature.