Matter that contain two or more constituent substances is called _____ .

Milk is an example of the type of matter called _____.

Water, mercury and bromine are similar to each other, because these three are _____ .

Valency of carbon is 4 and that of oxygen is 2. From this, we understand that there are ____ chemical bond/bonds between the carbon atom and one oxygen atom in the compound-carbon dioxide.

Identify the odd term out and explain.

Gold, silver, copper, brass.