Chpt. 2,4,5 Test

  1. Expain 2 things about elements.
    - all atoms in an element are the same, with the same number of protons in the nucleus

    -there are 92 naturally occuring, with more created in the lab
  2. Most gas elements are
    diatomic (2 atoms of the same element bonded)
  3. Explain 4 things about compounds.
    -made of more than 1 kind of atom (2/more elements)

    -atoms are bonded in a specific ratio

    -compounds may have physical properties completely different the the elements comprising them

    -there are bonding rights, so any two elements may not bond
  4. Explain 3 things about mixtures.
    -elements, compounds, E & C combined in no ratio and not chemically bonded

    -all componets retain their own physical & chmical prop.

    -mixtures can be homogeneous or heterogeneous
  5. particles very small and evenly distributed
  6. unevenly distributed like muddy water, pizza, oil, vinegar
  7. a change that does not change composition of a material
    physical change
  8. a change that changes a materials composition by creating new substances
    -release of a gas (bubbling, fizzing, not boiling)
    -"magical" color change
    -new odors are produced
    -"magical" temperature changes
    chmeical change
  9. the study of matter
  10. positively charged particles that are located inside the nucleus
  11. neutrally charged particles that are located inside the nucleus
  12. negatively charged particles located outside the nucleus in energy levels or orbitals
  13. Which sub-atomic particle is located outside the nucleus?
  14. in a neutral atom...
    each proton has an electron to cancel out the charge
  15. an atoms proton count is given by this
    atomic number
  16. whole number of protons and neutrons in a particular isotope and is always a whole number
    mass number
  17. weighted average of the masses of the isotopes of a particular element
    average atomic mass
  18. samples of the same element with a differing number of neutrons
  19. those created by man that have no isotopes and the avg. atomic mass = mass number
    synthetic elements
  20. states that an outer shell can only hold 8 electrons
    octet rule
Card Set
Chpt. 2,4,5 Test
atoms, elements, etc.