Dispersed phase and dispersion medium are the two components of a colloidal solution. The rest of the statements are incorrect as: (1) Combination of all the three phases, i.e. solids, liquids and gases, is not necessary to form a colloid. (2) The solute-like component or the dispersed particles in a colloid form the dispersed phase. (3) A colloid does not settle down when left undisturbed, i.e. a colloid is quite stable. 

A solution is defined as a homogeneous mixture of two or more chemically non–reacting substances whose composition can be varied within limits. If a mixture is to be called a solution, it must satisfy the following two conditions: (i) The components of a mixture should be non–reacting. (ii) Mixture should be homogeneous.

 The SI unit of pressure is pascal. 

SI unit of pressure is Pascal or Nm^-2.

The units of latent heat are  J kg^-1.

Matter cannot be classified on the basis of solubility.

Early Indian and Greek philosophers classified matter as ‘Panch Tatva’.

Its elements are combined in a variable proportion.

IUPAC (International Union of Pure and Applied Chemistry) approves the names of the elements. 

 Oxygen dissolved in water, being used for breathing by the aquatic life, is a true solution of gas in liquid. 

 The size of solute particles in suspension is more than 10^–5 cm.

Sunlight is dispersed when it passes through the canopy of a dense forest due to the presence of water droplets in the mist. 

Particles of matter cannot be seen with naked eye. 

This is the correct answer as both these statements are correct. 

A compound is a substance formed when two or more elements are chemically bonded together. Two types of chemical bonds common in compounds are covalent bonds and ionic bonds. The elements in any compound are always present in fixed ratios.