Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties. + 18 others found this useful. Jack Bakhet. Edit. Share to: Chrishan Silva. 509,209 Contributions. I'm an undergraduate in Physical Sciences stream.
1 Two gases make up the bulk of the earth's atmosphere: nitrogen (), which comprises 78% of the atmosphere, and oxygen (), which accounts for 21%. 2  Various trace gases make up the remainder. 3  Based on temperature, the atmosphere is divided into four layers: the troposphere, stratosphere, mesosphere, and thermosphere.
The gases that comprise the atmosphere are commonly referred to as air, which is what all living things on Earth breathe. Tip The majority of the air we breathe is made up of nitrogen and oxygen, though you'll also find argon, carbon dioxide and other gases in trace amounts. Nitrogen: Abundant and Inert Itâs a common misconception that oxygen is the most abundant gas in the air breathed on Earth; that honor goes to nitrogen, which makes up 78 percent of the air.