### Theory:

A chemical compound is formed when two distinct elements are chemically combined i.e. chemical bonds form between their atoms.
Example:
Salt $$NaCl$$

Water$$H_2O$$

Ozone $$O_3$$, Nitrogen dioxide $$NO_2$$, and so on.
Compounds are a form of matter created by combining two or more elements in a specific mass ratio. Chemical methods may be used to decompose it into its constituent components.

Properties of Compounds:

• Two or more elements are chemically mixed in a compound.
• The elements in a compound are present in a fixed mass ratio.
• Physical methods cannot isolate the constituents of a compound.
• The constituents of a compound lose their identities, i.e., A compound's properties vary from those of its constituent elements.
Example:
Constituent elements in a compound:

Water ($$H_2O$$) has three atoms: Two hydrogen (H) atoms and one oxygen (O) atom.

Methane  $$CH_4$$ with five atoms: One carbon (C) atom and four hydrogen (H) atoms.

Glucose  $$C_6H_{12}O_6$$ contains elements of carbon $$6$$, hydrogen $$12$$ and oxygen $$6$$ combined to form a glucose molecule.

Sodium chloride $$NaCl$$ contains the two elements: sodium and chlorine atoms combined to form a sodium chloride molecule.