GenChem Midterms

• Chemistry is the scientific discipline that studies the composition, structure, properties, and transformation of matter
• Democritus was the first to propose that matter exists in the form of particles
• Democritus coined the term "atoms" or atomos, meaning "uncuttable"
• Alchemists sought a universal solvent
• Alchemists tried to discover an elixir
• alchemists learned how to use metallic compounds and plant-derived materials to treat diseases
• Robert Boyle

  • formulated the fundamental gas laws,
  • first to propose the combination of small particles to form molecules
  • Differentiated between compounds and mixtures
• Evangelista Torricelli invented the mercury barometer
• J.L Gay Lussac

  • Discovered boron and Iodine
  • Discovered acid-base indicators (Litmus)
  • Improved method for making sulfuric acid
• Charles Coulomb Introduced the inverse-square law of electrostatics
• Michael Faraday

  • coined the term electrolysis
  • Developed theorist of electrical and mechanical energy
  • He was not a proponent of atomism
• The origins of chemistry can be traced back to ancient civilizations like Egypt, Mesopotamia(Ancient Greece), China and India
• The transition from alchemy to chemistry began in the 17th century with the work of scientists like Robert Boyle
• Robert Boyle was referred to as the Founder of Modern Chemistry
• The phlogiston theory dominated chemical thought here in the substance called Phlogiston was released during combustion. This was later Discredited by Antoine Lavoisier
• Antoine Lavoisier

  • The Father of Modern Chemistry
  • Introduced the concept of Oxidation
  • Introduced the law of conservation of mass
• The periodic table was formulated in 1869 by Dimitri Mendeleev here in the elements are organized based on their atomic mass and properties
• The discovery of Electrons, a subatomic particle with a negative charge, revolutionized the understanding of atomic structure. This was discovered by J.J Thompson
• The plum pudding model was proposed by J.J Thompson
• Ernest Rutherford proposed a new atomic model after conducting the famous gold foil experiment. His model; The Nuclear model suggested that atoms have a small, dense nucleus surrounded by electrons orbiting at a distance
• The development of quantum mechanics in the early 20th century by scientists like Niels Bohr, Werner Heisenberg, and Erwin Schrodinger.
• The discovery and development of synthetic polymers, such as nylon and polyethylene transformed materials science and everyday life.
• Chemists like Wallace Carothers at DuPont played pivotal roles in the synthesis of revolutionized materials
• The concept of Green Chemistry was introduced by Paul Anastas and John Warner in the 1990s, promoting a more sustainable and environmentally friendly future
• Significance Figures are an important concept in scientific measurement, as they indicate precision and reliability of a measurement
• Non-zero Digits are considered significant

  ex. .1989
• Leading zeros are not significant

  0.00562 (3 significant figures)
• Captive zeros - zeros between non-zeros are always significant

  ex. 108.04 .2002
• Trailing zeros in a decimal number are significant

  ex. 7.500
• Counting zeros

  Trailing zeros may or may not be significant
• Exact numbers have infinite number of significant figures
• Scientific Notation

  • is a system used to express numbers as the product of a coefficient and a power of 10.
  • representation of a very large or very small numbers
  • The coefficient in scientific notation should include all significant digits
• Large Numbers in Scientific Notation

  2,300,000 can be written as 2.3x10^8 by moving the decimal point six places to the left
• Small Numbers in Scientific Notation

  0.000045 can be expressed as 4.5x10^-5 by moving the decimal point five places to the right
• Speed of Light in Scientific Notation is approximately 299,792,458 meters per second. This is 2.99792458x10^8ms
• Unit Conversion is a fundamental skill in scientific and engineering. It allows us to express measurements in different units while preserving the underlying quantity being measured
• Matter is any substance that has mass and occupies space. All physical objects are composed of matter in the form of atoms and molecules which are composed of protons, neutrons, and electrons
• Solid

  • Particles are closely packed together, maintaining a fixed shape and volume due to strong intermolecular forces
  • Have definite shapes and volumes
• Liquid

  • More loosely packed
  • they move freely but remain close together due to weaker intermolecular forces
  • Have definite volumes but take the shape of their containers
• Gas

  • Particles are widely spaced, moving rapidly
  • Have little to no intermolecular forces
  • They expand their containers
  • Neither have definite shapes nor volumes