Victor 7th Grade Science Bonding Quiz Review

  1. What is an ionic bond?
    An Ionic bond is the attraction between two oppositely charged ions.

    When two ions come together, they do so in a way that balances out the charges on the ions.
  2. What is a Covalent bond?
    A covalent bond is a chemical bond formed when two atoms share electrons.  

    In a covalent bond, BOTH atoms attract the shared electrons at the same time.
  3. What is an ion?
    An ion is an atom or group of atoms that has become electrically charged.

    When an atom loses an electron, it loses a negative charge and becomes a positive ion.

    When an atom gains an electron, it gains a negative charge and becomes a negative ion.
  4. What are the properties of ionic compounds?
    The characteristic properties of ionic compounds include crystal shape, high melting points, and electrical conductivity.
  5. What is a chemical formula?
    A chemical formula is a combining of symbols to represent a molecule of a compound.  

    Each compound has its own chemical formula.  

    A formula tells us two very important things about a compound.  It tells us what elements the compound is made of and it tells us how many atoms of each element are in a compound.
  6. A chemical formula for a compound is always the same.

    A change in the formula means that a new compound was formed.  

    What is a number in front of a compound called?
    A number in front of a compound is called a coefficient.  It tells us how many molecules of that compound we have.

    Ex:     2H20

    The 2 in front of the H tells us the # of molecules.

    The lower 2 between the H and 0 tells us the number of atoms.
  7. Describe this formula...

    NaHCO3  is the formula for

    sodium hydrogen carbonate (baking soda)

    Elements it contains:

    Sodium (Na), Hydrogen (H), Carbon (C ), and Oxygen (O)

    The number of atoms of each element is:

    1 sodium, 1 hydrogen, 1 carbon, and 3 oxygen

    If we change the coefficient to some other number besides 1, it changes the number of atoms that we have: Formula = 4NaHCO3

    • You need to multiply all the number of atoms by the coefficient, so you will then have…
    • 4 sodium atoms, 4 hydrogen atoms, 4 carbon atoms, and 12 oxygen atoms.
Card Set
Victor 7th Grade Science Bonding Quiz Review
covalent bond, ionic bond, chemical bond, ions, electron transfer, ion formation