Ionic Compounds
Ionic compounds are made from which two types of elements?
A metal and a nonmetal.
Molecular compounds are made from what type(s) of elements?
Nonmetals only.
What prefix is used for “1” atom (only on the second element)?
Mono- (but omitted on the first element).
In a chemical reaction, the substances you start with are called _______.
Reactants
What is the rule about changing subscripts when balancing equations?
Never change subscripts, only add coefficients.
What happens to electrons in an ionic bond?
Electrons are transferred (metal loses, nonmetal gains).
In covalent bonding, what is shared between atoms?
Electrons are shared.
Name CO.
Carbon monoxide.
What does the arrow (→) mean in a chemical equation?
“Yields” or “reacts to form.”
Balance: __N₂ + __H₂ → __NH₃.
N₂ + 3 H₂ → 2 NH₃.
What does the formula NaCl represent: the exact number of atoms or the ratio of ions?
It represents the ratio of ions, not the exact number.
What type of bond forms in water (H₂O): single, double, or triple?
Single bond (between O and each H).
Name P₄O₁₀.
Tetraphosphorus decaoxide.
Write the word equation for: Fe + S → FeS.
Iron + sulfur → iron (II) sulfide + energy.
Which side of the equation is energy written on if the reaction absorbs energy?
On the reactant side (left).
Why do ionic compounds form crystal structures?
Positive and negative ions attract in a repeating pattern (opposites attract).
What type of bond forms in carbon dioxide (CO₂): single, double, or triple?
Double bond (C=O).
Write the formula for dicarbon tetrahydride.
C₂H₄.
What are the symbols (s), (l), (g), and (aq) used for in a chemical equation?
(s) = solid, (l) = liquid, (g) = gas, (aq) = aqueous (dissolved in water).
What is a catalyst, and what is a biological catalyst called?
A catalyst speeds up a reaction without being used up; a biological catalyst is an enzyme.
Write the chemical formula for calcium chloride.
CaCl₂.
Draw or describe the Lewis structure of methane (CH₄).
One carbon atom bonded to four hydrogens with single bonds, full octet for carbon.
Name CF₄, H₂O, and PF₅.
CF₄ = Carbon tetrafluoride
H₂O = Dihydrogen monoxide (common name: water)
PF₅ = Phosphorus pentafluoride
Balance the equation: __CH₄ + __O₂ → __CO₂ + __H₂O.
CH₄ + 2 O₂ → CO₂ + 2 H₂O.
Balance: __P + __O₂ → __P₄O₁₀.
4 P + 5 O₂ → P₄O₁₀.