Chemistry

• A solution with a pH of 7 is neutral (pure water).
• Acids have a pH less than 7, while bases have a pH greater than 7.
• The pH scale is logarithmic, meaning that each whole number change represents a tenfold increase or decrease.
• Acids have a pH less than 7.
• Bases have a pH greater than 7.
• The pH scale ranges from 0 to 14, where 0 is the most acidic and 14 is the most basic.
• Weak acids only partially dissociate into H+ ions when they are dissolved in water.
• Strong acids completely dissociate into H+ ions when they are dissolved in water.
• Bases can be strong or weak depending on how easily they release hydroxide ions (OH-) when dissolved in water.
• The pH scale ranges from 0 to 14, where 0 represents the strongest acid and 14 represents the strongest base.
• Bases can be strong or weak depending on their ability to accept hydrogen ions.
• Strong acids completely dissociate into H+ ions when they are dissolved in water, while weak acids only partially dissociate.
• Noble gases include Helium, Neon, Argon, Krypton, Xenon, Radon, and Oganesson.
• Alkali metals have low melting points and high reactivity with oxygen due to their large size and one valence electron.
• Group 7 elements form oxyanions by gaining electrons and forming negative ions.
• Transition metals have variable oxidation states and can form complex ions.
• s=2, p=6, d=10,f=14
• Elements in the same group have similar chemical properties because they have the same number of outer shell electrons.
• The periodic table is organized based on atomic number (number of protons) and electronic configuration.
• Electronic configurations determine how many electrons an atom has in its outermost energy level or shell.
• The periodic table is organized based on atomic structure, specifically the arrangement of protons, neutrons, and electrons within an atom.
• Electronegativity increases down a group as the effective nuclear charge decreases and the screening effect becomes less important.
• Atomic radius decreases across a period as the nuclear charge increases but the shielding effect remains constant.
• Ionic compounds consist of oppositely charged ions that are attracted to one another through electrostatic forces.
• Strong acid dissociation

  When a strong acid is dissolved in water, it undergoes complete dissociation, breaking apart into H+ ions (which become hydronium ions) and anions (conjugate bases). These ions can then participate in further chemical reactions.
• HCl dissociation


  When hydrochloric acid (HCl) is dissolved in water, it donates a proton (H+) to a water molecule (H2O), forming a hydronium ion (H3O+) and a chloride ion (Cl-), which is the conjugate base of HCl.
• Hydronium ion


  A hydronium ion (H3O+) is formed when a strong acid donates a proton (H+) to a water molecule (H2O). The hydronium ion can then participate in further chemical reactions.
• Conjugate base

  A conjugate base is the ion that remains after a strong acid donates a proton (H+) to a water molecule (H2O). The conjugate base can also participate in further chemical reactions.
• Categories of energy

  • Potential
  • Kinetic
  • Chemical
  • Nuclear
  • Stored Mechanical
  • Gravitational
  • Radiant
  • Thermal
  • Motion
  • Sound
  • Electrical
• Potential energy


  Stored energy and the energy of position (gravitational)
• Kinetic energy


  Energy in motion
• Chemical energy


  Energy stored in the bonds of atoms and molecules
• Examples of stored chemical energy

  • Biomass
  • Petroleum
  • Natural gas
  • Propane
  • Coal
• Nuclear energy


  Energy stored in the nucleus of an atom
• The nucleus of a uranium atom is an example of nuclear energy
• Stored mechanical energy


  Energy stored in objects by the application of a force
• Examples of stored mechanical energy

  • Compressed springs
  • Stretched rubber bands
• Gravitational energy


  Energy of place or position
• Example of gravitational potential energy


  • Water in a reservoir behind a hydropower dam
• When water is released to spin the turbines

  It becomes kinetic energy