Question

the name for al(oh)₃ is
aluminum(iii) hydroxide
aluminum hydroxide
aluminum trihydroxide
monaluminum trihydroxide
question 10
what is the formula for gold(i) oxide?
auo
auo₂
au₃o
au₂o

Explanation:

For the first question, aluminum has a common +3 oxidation - state and in naming simple ionic compounds like $\text{Al(OH)}_3$, we just name it aluminum hydroxide. The use of (III) is not necessary as aluminum usually has a +3 oxidation - state in common compounds and the prefixes like 'tri -' are not used in the standard naming of simple metal hydroxides.
For the second question, gold(I) has a +1 oxidation state and oxygen has a - 2 oxidation state. To balance the charges in the compound, we need 2 gold(I) ions for every 1 oxygen ion, so the formula is $\text{Au}_2\text{O}$.

Answer:

Question 9: aluminum hydroxide
Question 10: $\text{Au}_2\text{O}$