Problem 25
What do we mean when we say a chemical equation is balanced? Why do we balance chemical equations?
Problem 26
For a chemical reaction, what do we mean by the term reactants? What do we mean by the term products?
Problem 27
The combustion of a thin wire of magnesium metal (Mg) in an atmosphere of pure oxygen produces the brilliant light of a flashbulb, once commonly used in photography. After the reaction, a thin film of magnesium oxide is seen on the inside of the bulb. The equation for the reaction is $$ 2 \mathrm{Mg}+\mathrm{O}_{2} \longrightarrow 2 \mathrm{MgO} $$ (a) State in words how this equation is read. (b) Give the formula(s) of the reactants. (c) Give the formula(s) of the products.
Problem 28
Describe what kind of event must occur (involving electrons) if the atoms of two different elements are to react to form an ionic compound.
Problem 29
With what kind of elements do metals react?
Problem 30
What is an ion? How does it differ from an atom or a molecule?
Problem 31
Why do we use the term formula unit for ionic compounds instead of the term molecule? Can we use that term for molecules, atoms, and ions? Explain why.
Problem 32
Consider the sodium atom and the sodium ion. (a) Write the chemical symbol of each. (b) Do these particles have the same number of nuclei? (c) Do they have the same number of protons? (d) Could they have different numbers of neutrons? (e) Do they have the same number of electrons?
Problem 33
Define cation, anion, and polyatomic ion.
Problem 34
How many electrons has a titanium atom lost if it has formed the ion \(\mathrm{Ti}^{4+}\) ? What are the total numbers of protons and electrons in a \(\mathrm{Ti}^{4+}\) ion?
