Explain why during thunderstorms thunder

Electric sparks, piercing the air, instantly heat it, it expands sharply and produces a loud noise.
Lightning, piercing the air, instantly heats it, it expands sharply, making a strong noise (thunder).

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.