3. Ancient and medieval sword makers fashioned swords from metals and alloys. Apply your knowledge of the properties of metals and their alloys to explain the advantages and disadvantages of making swords from copper, bronze, iron, or steel.

Copper and iron swords were easier to make but less durable while bronze and steel swords were more effective for combat but more difficult to fashion.

Explanation:

Advantages-

Copper: It was a very common material and it could be sharpened easily. Iron: Like copper, very easy to find and harder than copper, so it is a better option to fabricate iron swords than copper swords. Bronze: Bronze is harder than copper and its rust is just shallow which makes bronze swords way durable in comparison.  With the materials in hand "copper and tin", it was easy to fabricate bronze swords on a great scale. Steel: This is the most durable and hardest of all the elements above.  

Disadvantages-

Copper: Easy to get rusty and be broken. Iron: Susceptible to severe oxidation, although it is more durable than copper. Bronze: As this is an alloy, it requires copper and tin, which it is not very common to find close to each other, so it makes it difficult to make bronze swords. Additionally, bronze weapons do not last very much; they are easy to break. Steel: Unlike bronze, steel rusting can wreck the sword if it is treated in time. Additionally, in ancient times, steel forges were very uncommon as not many knew the way to create steel from iron and carbon, so steel swords were very expensive and more likely to find in hands of kings and royal guards.

Hope this helps!

The mass has escaped into a gas which you can not see so the law stays true.

The correct answer is "atomic weight".