Answer:
use dimensional analysis.
Step-by-step explanation:
The best advice I can give you is to look up the molar mass of each of the elements in the table. remeber that molar mass is grams of a substance per mole or G/mol. For example the molar mass of Ti is 47.87 g/mol and we are given 23.4 mg. if we convert that 23.4 mg into grams, we can divide the 47.87 by it to find moles.