It is a mixture because the compounds that make up air e.g. oxygen (o2), Carbon dioxide (co2) and the most important Nitrogen which is an element and makes up 78.09% of air are not chemically bound in the way that compounds are because they can be separated easily and there has been no change in state to any of the compounds or elements in air!hope this helpful!
Here's the Answer !
Atomic number = no. of electrons = no. of protons, therefore :
and mass number = no. of protons + no. of neutrons
so,
Neutrons were discovered by James Chadwick<span> in 1932, when he demonstrated that penetrating radiation incorporated beams of neutral particles. Neutrons are located in the nucleus with the protons. Along with protons, they make up almost all of the mass of the </span>atom<span>.
Hope this helps. </span>
Special Structures in Plant Cells. Most organelles are common to both animal and plant cells. However, plant cells also have features that animal cells do not have: a cell wall, a large central vacuole, and plastids such as chloroplasts.