chem mt

• Electron - Negatively Charged particle (-1)
• Proton - Positively Charged particle (+1)
• Neutron - Neutral uncharged particle
• Proton and Neutron combine to form the nucleus in the center of the atom while the electrons move around the nucleus
• Atomic number - number of protons
• Number of protons is always equal to number of electrons. Since the positively charge is equal to negative charge the charge of an atom is neutral.
• gain or lose electrons to form a charged particle called Ion
• Mass number - total number of protons and neutrons
• Mass number is the weight of the atom in atomic mass unit or AMU
• Isotopes - same atomic number and different mass number
• Commons isotopes is Uranium used in Nuclear reaction
• Electrons move about the nucleus along the Shells or Energy Levels
• Principal Quantum Numbers - denoted by n, coefficient of subshells or Energy Level of an electron
• Azimuthal Quantum Numbers - denoted by p, shapes of orbital, number of nodes.
• Magnetic Quantum Numbers - denoted by Mp, angular momentum corresponding to the orbital along a given axis.
• Electron Spin Quantum Numbers - denoted by Ms, direction of the spin
• Chemistry -A branch of science that deals with the composition and structure of materials and the changes they undergo.
• Matter - Anything that occuipies space and has mass
• Element - Substance that cannon be broken down or separated into simpler substance by chemical reaction.
• Compound - Composed of atoms of two or more elements chemically united in fixed proportions.
• Mixtures - A composition of two or more substance
• Homogeneous Mixtures - uniform, hard to distinguish
• Heterogeneous Mixture - composition varies, easy to distinguish
• Substance - A form of matter that has definite composition and distinct properties
• Solid - Compact and has definite shape
• Liquid - Accepts the shape of its container in which it is held
• Gas - Expands to occupy the volume of its container
• Pure Substances - cannot be seperated into other kinds of matter by any physical means
• Plasma - hot gas that carry electrical charge
• Bose-Einstein Condensate - subatomic particles cooled near to absolute zero
• Nucleus - surrounded by a disperse cloud of electrons
• Ionic bonding - transferring of electrons, one substance loses and electrons to become cations
• Covalent bonding - electrons shared in pairs
• In Periodic Table horizontal rows called Periods, Vertical rows called Groups
• Pauli's Exclusion Principle - no two electrons can share the same combination / occupy a single orbital
• Hund's Rule - Every orbital in a sublevel is singly occupied before any orbital is doubly occupied. Place up spin direction before pairing individual orbitals
• Sharp (s), Principal (p) diffuse (d) Fundamental (f)
• Aufbau's Principle - suggest the order of occupancy of sublevels
• Electronic Configuration - shows the distribution of the electrons of an atom
• Electron Dot - distribution of valence electrons of an element