1. Other than Nitrogen, Oxygen, and other gases our air contains variable amount of what and by how many percent?

78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases.[8] Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere. Air composition, temperature, and atmospheric pressure vary with altitude, and air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is found. only in Earth's troposphere and in artificial atmospheres.

a) the particles of the chair are strongly held together.