Pure air is a mixture of several gases that are invisible and odorless. Consists of 78% nitrogen, 21% oxygen, and less than 1% of argon, carbon dioxide.
Answer:
I didn't do the observation so I can't help sorry
Alchemists advanced the tools and procedures for working with chemicals. Alchemists also developed methods for sorting out mixtures and cleansing chemicals. They designed equipment that is still in use today including beakers, flasks, tongs, funnels, and the mortar and pestle. Also, Alchemists backed to an unbelievable variety of what would later be acquainted as chemical industries: basic metallurgy, metalworking, the invention of inks, dyes, paints, and cosmetics, leather-tanning, and the preparation of extracts and liquors.
The theory that describes the motion and force driving earth's plates is Plate tectonics
Explanation:
Plate tectonics states that the outer shell of the Earth is divided into plates that glide and move over the mantle which is the surface of the earth.
The mantle is the rocky inner layer above the core of the Earth.
Plate tectonics helped the geologists to explain how continents could move around the planet.
There are 9 major plate tectonics , namely North American, Pacific, Eurasian, Australian, African, Indo - Australian,Indian South American and Antarctic. These plates have been named after the land form found on them.