Name ____________________________________ Date ___________________ Class Period ____________
Compound Notes Review
(1) A pure substance is called an _______________ (made of only 1 type of ________).
However, when 2 or more _____________ elements combine a __________________ is
formed. When a compound is formed a completely _______ ____________ is created. For
example, hydrogen (H) and oxygen (O) are two gases that combine to create a ________ H2O.
(2) ________________ can be represented by chemical ____________. Each different element
in a compound is represented by a unique ____________. The ___________ of each type of
element in the compound (other than 1) is represented by a ________ ___________ (called the
SUBSCRIPT) to the _________ of the element symbol. A _______________ is the smallest
piece of a compound. A compound, unlike an element, _____ ______ broken apart by chemical
means.
CO2
(3) Chemical ________________ are used to show chemical changes needed to make
compounds. A CHEMICAL EQUATION contains __________, addition ________, and an
arrow to show what compound the ___________ yields. A equation also contains
______________ to show number of atoms and a large number (the _________________) to
the left of the element symbol to show the number of __________________.
2Na + O2 + H2  2NaOH
(4) Reminders: *Each element is ____________________ by its ___________ from the
periodic table. An element symbol by with only ______ letter is always ________________.
In an element with two letters, the first letter is capitalized and the second letter _______ be
lower case. **The _________________ tells the number of _________________.
Compound Notes
(1) A pure substance is called an ELEMENT (made of only 1 type of atom. However, when 2
or more different elements combine a COMPOUND is formed. When a compound is formed a
completely new substance is created. For example, hydrogen (H) and oxygen (O) are two gases
that combine to create a liquid H2O.
(2) Compounds can be represented by chemical formulas. Each different element in a
compound is represented by a unique symbol. The number of each type of element in the
compound (other then 1) is represented by a small number (called the SUBSCRIPT) to the right
of the element symbol. A molecule is the smallest piece of a compound. A compound, unlike an
element, can be broken apart by chemical means.
CO2
(3) Chemical equations are used to show chemical changes needed to make compounds. A
CHEMICAL EQUATION contains formulas, addition signs, and an arrow to show what
compound the equation yields. A equation also contains subscripts to show number of atoms
and a large number (the COEFFICIENT) to the left of the element symbol to show the number
of molecules.
2Na + O2 + H2  2NaOH
(4) Reminders: *Each element is represented by its symbol from the periodic table. An
element symbol by with only one letter is always capitalized. In an element with two letters,
the first letter is capitalized and the second letter must be lower case. **The coefficient tells the
number of molecules.