A Japanese sword maker heats a mixture of iron and charcoal. He repeatedly heats, folds, and flattens the mixture more than a thousand times.
What is he doing?
a. He is making a metallic bond and adding impurities.
b. He is making an ionic compound and removing impurities.
c. He is making an alloy and removing impurities.
d. He is making an iron ore and adding impurities.
