Weight is affected by gravitational force
A. is the correct answer.
when an optical telescope located on the ground is used to view the sky the image has to surpass through the earth's atmosphere which is polluted. so the resolution wont be clear. When viewed on a mountain top both optical and infrared telescopes would perform better as the air above the atmosphere is less depth and cleaner.
Answer: AIP
There are two types of substances mixture and pure substance. Mixture has NO chemical formula and a pure substance has a chemical formula. There are two types of pure substances, elements (mono atomic and molecular) and compounds ( covalent and ionic).
Ionic compounds do not exist in independent molecular form. They form three dimensional crystal lattice, in which each ion is surrounded by oppositely charged ion. so the ratio of ion is called the formula unit