Answer:
option (d) 17.7%
Explanation:
Data provided in the question:
Mass of the ore of copper extracted from the backyard = 65.0 grams
Mass of the copper extracted from the ore of copper = 11.5 grams
Now,
The mass percent of copper discovered
= [ ( Mass of the copper extracted ) ÷ ( Mass of the copper ore extracted ) ] × 100%
= [ 11.5 grams ÷ 65.0 grams ] × 100%
= 17.692% ≈ 17.7%
Hence,
the answer is option (d) 17.7%