chemistry

Subdecks (9)

Cards (310)

  • atomic number is the number of protons in the nucleus of an atom, which is equal to the number of electrons in the outermost shell
  • mass number is the total number of protons and neutrons in the nucleus of an atom
  • the periodic table arranges elements by increasing atomic number
  • isotopes are atoms with different numbers of neutrons but same atomic number
  • groups on the periodic table have similar chemical properties because they have the same number of valence electrons
  • groups are columns on the periodic table that contain elements with similar properties
  • periods are rows on the periodic table that contain elements with similar electron configurations
  • relative atomic mass (A) is the weighted average of all naturally occurring isotopes of an element
  • elements in group 1 have one valence electron
  • a molecule is two or more atoms bonded together
  • an ion is an electrically charged particle formed when one or more electrons have been gained or lost
  • elements are arranged according to atomic number
  • periodic table families include:
    • alakali metals
    • non alakali metals
    • halogens
    • noble gases
    • boron family
    • carbon family
    • nitrogen family
  • atomic orbitals are the regions of space around the nucleus where electrons can be found
  • the s orbital has spherical shape, while p orbitals have dumbbell shapes
  • electron configuration refers to how many electrons occupy each energy level
  • ionization energy is the amount of energy required to remove an electron from an atom or ion
  • metalloids are elements that exhibit properties between metals and non-metals
  • atomic radius is the distance between the nucleus and the outermost electron shell in an atom
  • more protons=smaller atomic radius
  • shielding effect: the reduction in the net positive charge felt by the valence electrons due to the repulsive effect the core electrons have on valence electrons (reduces columbic attraction)
  • coulombic attraction: the attractive force between protons & electrons
  • coulombic attraction decreases down a group (increases left to right across a period)
  • ionic radius is the distance between the positive and negative ions in an ionic compound
  • groups 1a-3a loose valence electrons & become cations (positively charged ions)
  • groups 5a-7a gain additional valence electrons to become anions (negatively charged ions)
  • octet rule: the number of electrons in the outermost energy level of an atom is equal to the number of protons
  • electronegativity: the ability of an atom of an element to attract electrons towards itself in a chemical bond
  • noble gases do not have electronegativity values & do not loose/gain electrons
  • electronegativty increases up a group and left to right across a period
  • Bohr model: electrons are located in an atomic orbital (sublevels of an energy level)
    • closer energy level has electrons that have a stronger attraction to the nucleus
    • to move from level to level, an atom must gain or loose a quantum of energy
    • 7 energy levels & 4 sublevels= s, p, d, f
    • 1= s orbital, 2= s, p orbitals, 3= s, p, d, orbitals, 4-7= s, p, d, f orbitals
    • electrons in the same orbital must have opposite spins
    • electrons occupy empty orbitals first
  • C= wavelength times frequency

    C= speed of light (3.00 times 10^8 m/s)
  • photoelectric effect: when an atom is given excess energy, it jumps to a higher energy level (excited state)