The correct answer would be B for sure
Answer:

Explanation:
We will need an equation with masses and molar masses, so let’s gather all the information in one place.
M_r: 315.46 76.12
Ba(OH)₂·8H₂O + 2NH₄SCN ⟶ Ba(SCN)₂ + 2NH₃ + 10H₂O
m/g: 6.5
1. Moles of Ba(OH)₂·8H₂O

2. Moles of NH₄SCN
The molar ratio is 2 mol NH₄SCN:1 mol Ba(OH)₂·8H₂O

3. Mass of NH₄SCN

Answer:
B.Bronze is harder than copper, so it retains a cutting edge sharper than that of copper.
Explanation:
The importance of bronze in the history of the human kind can not be only measured in the durability but the help that it provided to our ancestors, the things they were allowed to do once they dicovered how to mold it, and the tools that they produced and made many every day tasks easier for them and the ability of bronze to mantain the cutting edge longer than copper was one of the main reasons why it took its places in the fabrication of many tools.