1) Consider the following list of common substances.
| air | brass | glass | limestone |
| salt | sugar | water | |
Choose from this list a substance which
(a) is a mixture containing both elements and compounds.
(b) is a mixture of compounds
(c) is a mixture of elements
(d) is a compound containing only two element
(e) is a compound which contains carbon
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Answer:
(a) air
Air is a mixture of elements such as oxygen, nitrogen,and compounds such as carbon dioxide and water vapor.
(b) glass
Glass is an amorphous mixture of compounds including sand/silica, sodium oxide, calcium oxide and so forth.
(c) brass
Brass is a mixture of 2 elements of Cu and Zn.
(d) water
Water is a compound in which hydrogen and oxygen chemically react together to form H2O.
(e) sugar
Sugar is an organic compound. (Organic implies carbon containing) For example, table sugar consists of sucrose (C12H22O11)
