CHEMISTRY SCIENCE 9 Q2

• Matter


  Anything that has mass and occupy space.
• Atom


  Smallest unit of matter and building blocks of matter.
• Protons


  Are the positively charge particles.
• Electrons


  Are the negatively charge particles.
• Neutrons


  Are the uncharged particles neither positive nor negative.
• Energy level


  Fixed energies that the electrons have.
• Atomic orbital


  Volume or region of space around the nucleus where the electron is most likely to be found.
• Quantum mechanical model


  Describes the atoms as having nucleus at the center around which electrons move.
• Electron configuration


  The way in which electrons are distributed orbitals around the nucleus of an atom.
• Aufbau's principle


  Lower energy level must be filled first before filling the next energy level.
• Hund's Rule


  Electrons are filled in one at a time before pairing.
• Metalloids


  A unique group of elements that share properties of both metals and non-metals.
• Compounds


  Are the chemical substances made up of two or more elements.
• Compounds


  Are the chemical substances made up of two or more elements that chemically bound together.
• Chemical Bonding


  A lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds.
• Onic Bonding


  Is formed complete transfer of electrons from one atom to another atom.
• Valence electrons


  Are the electrons directly involved in forming bonds to form compounds.
• Electronegativity


  Is a measure of the tendency of an atom to attract electrons, the higher its tendency to attract electrons.
• Ionization energy


  Is the energy needed to pull or remove or more electron/s from a neutral atom.
• Covalent Bonding


  Also called molecular bond, it is a chemical bond that involves sharing of electrons pair between atoms.
• Molecules


  A compound could exist as independent unit.
• Lewis symbol


  Is composed to the symbol of the element and dots represent the number of valence electrons of an atom that can easily be determined through the family/group number in the Periodic Table of Elements.