Chemistry 2

  1. Atom
    The smalllest particle of an element that retains the identity of the element
  2. Electron
    A negatively charges particle within the atom
  3. Subatomic particle
    A particle that is smaller than the atom
  4. Nucleus
    In chemistry, the positively charged center of an atom 
  5. Proton
    A positively charged particle that is part of every atomic nucleus
  6. Neutron
    • An uncharges particle that is part of almost every atomic nucleus
    • (the number of neutron in an atom in atomic mass substracted by the atomic number)
  7. Energy levels
    A possible level of energy an electron can have in an atom
  8. Atomic number
    • The number of protons in the nucleus of an atomImage Upload 1
    • (22 is the atomic number)
  9. Mass number
    The sum of the number of protons and the number of neutrons in the nucleus of an atom
  10. Isotope
    one of two or more forms of an element that have the same number of protons but a different number of neutrons
  11. Bohr-Rutherford diagram
    • A model of the atom in which a central positive nucleus is surrounded by electrons in energy level
    • e.g.Image Upload 2
  12. Atomic mass
    The average mass of the naturally occurring isotopes of an element
  13. Periodic table
    • A system for organizing the elements into columns and rows, so that elements with similar properties are in the same ¬†column
    • Image Upload 3
  14. Metal
    • Typically, an element that is hard shiny, malleable and ductile, and is a good conductor of heat and electricity
    • e.g. copper ,silver, gold
  15. Non-metal
    • typically, an element that is not shiny, malleable, or ductile and is a poor conductor of heat and electricity
    • e.g.Hydrogen, oxygen, carbon
  16. Metalloids
    • An element that shares some properties with metals and some properties with non-metals
    • e.g. silicon, arsenic
  17. Period
    A horizontal row of elements in the periodic table
  18. Group
    A vertical column of elements in the periodic table
  19. Alkali metal
    • Group 1
    • have low melting points
    • highly reactive
  20. Alkaline earth metal
    • group 2
    • highly reactive(less than alkali metals)
    • will burn in air
  21. Halogens
    • Group 17
    • Non-metal
    • highly reactive
    • extremely corrosive
  22. Noble gases
    • Group 18
    • Non-metal
    • colorless
    • gas
    • non-reactive
  23. Valence electron
    An electron in the outermost occupied energy level of an atom
Card Set
Chemistry 2
chapter 5