An alloy is a mixture of two or more metals which is produced with a specific proportion between metals. So, if the proportion is changed the physical characteristic would be changed as well. For example, brass musical instruments are made of brass which is a mixture (an alloy) of zinc and copper in a specific proportion. If you change a proportion, you will change the physical characteristic of brass musical instruments, and a sound they produce will be different.
The answer is c. unchanged........
It condenses when it passes below 212 degrees Celsius, or 100 degrees Fahrenheit
They will attract each other. Similar to the saying opposites attract.