What is the physical composition of our air? What types of things is our air made
up of? Describe what it may look like, its
size, etc.

The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. Air also has small amounts of lots of other gases, too, such as carbon dioxide, neon, and hydrogen

Components of Air - Oxygen, Nitrogen, Carbon dioxide, Water Vapour

Properties of Air

Colourless and Odourless: Air generally has no colour or odour

Occupy space: It is a mixture of different gases

Air exerts pressure: It has weight, and the pressure exerted by the weight of air is known as air pressure

Expansion: Another property is its expanding property.

Explanation:

Hope this helps:)

Air is mainly a mixture of two gases.

Explanation:

Air is mainly a mixture of two gases, nitrogen (around 78%) and oxygen (around 21%). It also contains carbon dioxide (around 0.03%), noble gases (around 0.9%), water vapour and a very small amount of other kinds of gases. Air makes up the atmosphere, which is essential for life on Earth.

(FYI, argon has the highest percentage of composition among the noble gases)

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.