What are the top three material by weight in a computer

More than 500 pounds of fossil fuels alone are guzzled up--several times the weight of your computer--not to mention nearly 50 pounds of chemicals, and 1.5 tons of water. Metals, silicon and petroleum are among the main raw materials that undergo several transformations (largely through the intensive use of chemicals) to fit neatly in your computer's sleek casing. This is off a website.