AI Explain

• Everything is made of atoms
• Atoms


  Consist of a core and some electrons. The core is made of protons and neutrons.
• Elements


  Different elements are determined by the number of protons
• Elements


  • Water (Hydrogen and Oxygen)
  • Sodium
• Quantum mechanics tells us that atoms do not actually look like the simple model of a core and electrons
• Electron shells


  Atoms have multiple electron "shells". The electrons in the outermost shell are called "valence electrons".
• Most of chemistry is the behaviour of valence electrons
• The periodic table lists all elements
• Groups in the periodic table

  Elements in the same column or "group" have the same number of valence electrons
• Valence electrons


  For the main groups, the number of valence electrons is just the group number from 1 to 8, except for helium which has 2
• The transition metals do not follow a simple pattern in the periodic table
• Alkali metals


  The first group, without hydrogen, is called the "alkali metals". They have one valence electron, are shiny metals, are kind of soft, and react in a certain way.
• Periods in the periodic table


  All elements in the same row or "period" have the same number of shells, which increases from top to bottom. The mass also gets bigger from left to right.
• Isotopes


  Depending on the number of neutrons in the core, you get different isotopes of the same element, most of which are unstable and radioactive.
• Radioactive isotopes can be harmful and "will kill you"
• Ions


  If an atom has the same amount of electrons as protons, it has no charge. If it has more, it has a negative charge (anion), and if it has less, it has a positive charge (cation).
• Periodic table information


  The periodic table provides the name, symbol, number of protons, and atomic mass of each element.
• Periodic table categories


  The periodic table is roughly divided into metals, non-metals, and semimetals.
• Molecules


  Two or more atoms bonded together form a molecule. If you have at least two different elements, you get a "compound".
• Compounds often behave completely differently than the elements they're made of
• Molecular formula


  A way to write molecules by counting the number of each atom and writing them as a subscript number next to the element symbol.
• Isomers


  Molecules with the same molecular formula but different structures.
• Lewis-Dot-Structure


  A way to show the structure of an atom by representing the valence electrons and bonds as dots and lines.
• Atomic stability


  Atoms want to achieve a state of lower energy, which is having a full outer shell of electrons, usually 8 or 2 for hydrogen and helium.
• Covalent bond


  The sharing of electrons between atoms to achieve a full outer shell, caused by the positively charged nucleus tugging on electrons.
• Electronegativity


  The strength of an atom's pull on electrons, which increases from bottom left to top right in the periodic table.
• Ionic bond


  When the difference in electronegativity is greater than 1.7, one atom completely transfers an electron to another, forming a cation and anion.
• Ionic bond example


  • Sodium Chloride (table salt)
• Metallic bond


  In a metal, the valence electrons are "delocalized" and can move freely, which gives metals their properties like conductivity and malleability.
• Nonpolar covalent bond


  When the difference in electronegativity is less than 0.5, the electrons are shared equally.
• Polar covalent bond


  When the difference in electronegativity is between 0.5 and 1.7, one element pulls the electrons harder, creating a partial charge.
• Polar covalent bond example


  • Water
• Electric dipole


  The presence of two poles with opposite charge in a polar molecule.
• Intermolecular forces (IMFs)


  The forces acting between polar molecules that cause them to arrange with oppositely charged ends next to each other.
• Hydrogen bond


  A specific type of IMF where hydrogen bonds to a highly electronegative element like fluorine, oxygen or nitrogen.
• Solvent properties of water

  Water can dissolve polar and ionic substances by tugging on charges, but cannot dissolve nonpolar molecules.
• "Similia Similibus Solventur" - similar things will dissolve similar things
• Van der Waals forces

  Electrostatic forces that arise from the temporary, random dipoles that form in nonpolar molecules.
• Surfactants


  Soap molecules with a polar "head" and nonpolar "tail" that can surround and transport nonpolar dirt particles.
• Strength of bonds and forces

  • Ionic Bonds
  • Covalent Bonds
  • Metallic Bonds
  • Hydrogen Bonds
  • Van der Waals Forces