Chemestry🧪⚗️

• The number of the well known elements up till now is 118 elements
• Classification of elements according to their properties and electronic structure

  • Metals
  • Nonmetals
  • Noble (inert) gases
• Metals


  Elements which have less than four electrons in the outermost shell, have luster, are good conductors of heat and electricity, malleable and ductile
• Nonmetals


  Elements which have more than four electrons in the outermost shell, have no luster, are bad conductors of heat and electricity (except graphite is good conductor of electricity), not malleable or ductile
• Noble (inert) gases


  Elements which don't participate in any chemical reaction in ordinary conditions due to the completeness of their outermost energy levels with electrons
• Ion


  Atom of an element which loses or gains an electron or more during the chemical reaction
• Types of ions


  • Positive ion
  • Negative ion
• Positive ion


  Atom of a metallic element that loses an electron or more during the chemical reaction
• Negative ion


  Atom of a nonmetallic element that gains an electron or more during the chemical reaction
• Ionic bond


  Chemical bond resulting from the electric attraction between a positive ion and a negative ion
• Ionic bond


  • NaCl
  • MgO
• Single covalent bond


  Chemical bond which arises between two nonmetal atoms by sharing of one pair of electrons, where each atom shares with one electron
• Single covalent bond


  • H₂
  • H₂O
• Covalent bond


  Chemical bond originated between the atoms of nonmetals through sharing of each atom with a number of electrons to complete the outer electron shell of each atom
• Types of covalent bonds

  • Single covalent bond
  • Double covalent bond
  • Triple covalent bond
• Double covalent bond


  Chemical bond which arises between two nonmetal atoms by sharing of two pairs of electrons, where each atom shares with two electrons
• Double covalent bond


  • O₂
• Triple covalent bond


  Chemical bond which arises between two nonmetal atoms by sharing of three pairs of electrons, where each atom shares with three electrons
• Triple covalent bond


  • N₂
• Metals


  Located on the left side and the middle of the periodic table, metals are shiny, solid (except for mercury), good conductors of heat and electricity, and tend to lose electrons in chemical reactions.
• Positive Ion


  An atom that has lost one or more electrons, resulting in a positive charge.
• Negative Ion


  An atom or molecule that has gained one or more extra electrons, resulting in a negative charge. Also known as an anion.
• Neutral Ion


  An atom or molecule that has not gained or lost any electrons, resulting in a neutral charge.
• Ionic Bond


  A type of chemical bond that forms between a positive ion (cation) and a negative ion (anion) due to their electric attraction. This bond creates a stable compound.
• Ion


  An atom or molecule that has a positive or negative electrical charge, created when the atom or molecule gains or loses one or more electrons.
• Positive ion (cation)


  An ion that has lost one or more electrons and has a positive charge.
• Negative ion (anion)


  An ion that has gained one or more electrons and has a negative charge.
• Electric attraction


  The force that holds positive and negative ions together in an ionic bond, created by the attraction between opposite charges.
• Ionic bond formation


  The process in which positive and negative ions come together and are held together by their electric attraction, forming an ionic compound.
• Lattice energy


  The energy released when ions come together to form an ionic compound, a measure of the strength of the ionic bond.
• Ionic bond strength


  Determined by the charges of the ions and the distance between them. Greater charges and shorter distances result in stronger bonds.
• Ionic compound properties


  High melting and boiling points, a crystalline structure, and the ability to conduct electricity when melted or dissolved in water.
• Metals

  • Metals 2
• Positive Ion

  An atom of a metallic element that loses an electron or more during the chemical reaction
• Negative Ion

  An atom of a nonmetallic element that gains an electron or more during the chemical reaction
• Ion

  An atom which loses or gains an electron or more during the chemical reaction
• Ionic Bond

  A chemical bond resulted from the electric attraction between a positive ion and a negative ion
• Covalent Bond

  A chemical bond originated between the atoms of nonmetals through sharing of each atom with a number of electrons to complete the outer electron shell of each atom
• Single Covalent Bond

  A chemical bond that arises between two nonmetal atoms by sharing of one pair of electrons, where each atom shares the other atom with one electron
• Double Covalent Bond

  A chemical bond that arises between two nonmetal atoms by sharing of two pairs of electrons, where each atom shares the other atom with two electrons