Answer:
D. 0.75 grams
Explanation:
The data given on the iridium 182 are;
The half life of the iridium 182,
= 15 years
The mass of the sample of iridium, N₀ = 3 grams
The amount left, N(t) after two half lives is given as follows;

For two half lives, t = 2 × 
∴ t = 2 × 15 = 30


∴ The amount left, N(t) = 0.75 grams
The type of chemical reaction that the reactants will undergo would be a single displacement reaction.
In a single displacement reaction, one element gets substituted or replaced by another element in a compound. This often leads to the formation of a new compound (aqueous) and a new element (solid or precipitate).
Thus, the complete equation of the reaction becomes:

Cu displaced Ag from AgNO3. Thus Ag becomes precipitated in solution while a new compound, CU(NO3)2 is formed.
More on displacement reactions can be found here: brainly.com/question/13219117