so basically
some fuels have an impurity in them which is sulfur.
When the fuel undergoes combustion, the sulfur reacts with oxygen in the air to form sulfur dioxide.
the sulfur dioxide reacts with water vapour in the air to form sulfurous acid, which is a type of acid rain.
Also
the high pressures inside a car engine may cause nitrogen and oxygen in the air to react and form oxides of nitrogen. the most common compounds formed inside car engines are NO (nitrogen oxide) and NO2 (nitrogen dioxide)
<u>Explanation:</u>
A balanced chemical equation is one where all the individual atoms are equal on both sides of the reaction. It follows the law of conservation of mass.
When potassium phosphate reacts with silver nitrate, it leads to the formation of silver phosphate and potassium nitrate.
The balanced chemical equation follows:

When barium bicarbonate reacts with calcium hydroxide, it leads to the formation of barium carbonate, calcium carbonate and water
The balanced chemical equation follows:

Ionic bonding is formed in Ionic compounds due to electrostatic force between the oppositely charged ions.
In covalent bonds electrons are shared between the atoms. In case of ionic bond the bond is stronger as there is complete transfer of electrons from one ion to the other.
Since the ionic bonds are more difficult to break than the covalent bonds, ionic compounds have a higher melting point than covalent compounds.
Answer:

Explanation:
The relation between frequency and wavelength is shown below as:

c is the speed of light having value 
Given, Frequency = 1290 kHz =
(As 1 kHz = 1000 Hz )
Thus, Wavelength is:


