State of Matter

Option “A” is correct.
Diamond is an element. It is not a compound as compounds contain several elements. Additionally, diamond is not a mixture since a mixture is either a solution or a mix of various elements in unequal ratios. For example, bronze is a mixture of copper and tin.

Option “C” is correct.
Maharshi Kannada, an ancient Indian was perhaps the first to suggest that matter is made up of very tiny particles called anu (molecule) which is formed of further smaller particles called as parmanu (atom).
Democritus named atom.
John Dalton suggested that something smaller called atoms make up the matter.

Option “D” is correct.
Ammonia, NH3, is a chemical compound composed of one nitrogen atom and three hydrogen atoms. Ammonia is a colorless gas that is lighter than air, and can be easily liquefied. Ammonia is a compound normally encountered as a gas and has a strong odor.

Option “D” is correct.
Diamond is an element. It is not a compound as compounds contain several elements. Additionally, diamond is not a mixture since a mixture is either a solution or a mix of various elements in unequal ratios. For example, bronze is a mixture of copper and tin.

Option “C” is correct.
Air is a mixture and not a compound because of the following reasons: Air can be separated into its constituents such as oxygen, nitrogen etc. by fractional distillation of liquid air. Air shows the properties of all the gases present in it.

Option “C” is correct

Option “B” is correct.
Steel is a mixture of iron and carbon fused together with one or more other metals or nonmetals. Because steel is a mixture rather than a chemical compound, steel does not have a set chemical compound formula.

Option “C” is correct.
A pure element is one which constitutes of similar kind of atoms. Thus, sodium is a pure element having only sodium atoms. While glass and cement are made up of different kinds of atoms.

Option “A” is correct.
Since, every atom is also known as element.
Hence a pure substance containing only one type of atom is called an element, and containing only one type of molecule is called a compound.

Option “B” is correct.
Compounds are chemical substances made up of two or more elements that are chemically bound together in a fixed ratio. For example, Water H 2 O is a compound made with two different substances called Hydrogen and Oxygen.