Answer:
To find the amount of zinc needed, calculate 2/10 (2 kg total, with a 2:8 ratio of zinc to copper) and then multiply by the total mass (2 kg) to get the grams of zinc.First, determine the fraction of zinc in the 2:8 ratio:
\( {2}{2+8} = \{1}{5} \)
Now, multiply this fraction by the total mass (2 kg) to find the grams of zinc needed:
{1}{5} \times 2000 \, t{g} = 400 \, \t{g} \)
You would need 400 grams of zinc to make 2 kg of brass with a 2:8 zinc-to-copper ratio.