a subtances are?
paki sagot
Answers
Answer:
A substance is a matter that has definite properties and composition. Every pure compound and element is a substance. Water, H2O, is a pure substance, a compound made of hydrogen and oxygen. Every pure substance is homogeneous. Pure substances can be divided into two categories – elements and compounds.
(i) A substance that has a fixed chemical composition throughout is called a pure substance such as water, air, and nitrogen. A pure substance does not have to be of a single element or compound.
(ii) • Pure substances are mostly homogeneous in nature containing only one type of atoms or molecules.
• These substances mainly have a constant or uniform composition throughout.
• The substances have fixed boiling and melting points.
• A pure substance usually participates in a chemical reaction to form predictable products.
(iii) :- Appearance - A pure substance is usually all one color. The exception is if the matter has unusual optical properties, such that it reflects or refracts light. A pure substance has the same appearance and properties, no matter where you sample it. If you magnify the matter, it should appear the same everywhere in its composition..
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