Explanation:
Definition of Lightning:
- Lightning is a natural electrical discharge of very short duration and high voltage between a cloud and the ground, between two clouds, or between two parts of the same cloud.
True Statements about Lightning:
- A: A brilliant flash of light is called a spark.
- B: A single flash of lightning is called a lightning bolt.
- C: Lightning can lead up to a thunderstorm.
Explanation of True Statements:
- A: A spark is a small, bright, and visible electrical discharge that occurs when there is a rapid movement of electrons. In the case of lightning, the brilliant flash of light that we see is the result of a spark.
- B: A lightning bolt refers to a single flash of lightning that we observe during a thunderstorm. It is a visible manifestation of the electrical discharge between the cloud and the ground, or between different parts of the cloud.
- C: Lightning is often associated with thunderstorms. Thunderstorms are characterized by the presence of thunder and lightning. Lightning can be one of the leading indicators that a thunderstorm is occurring or about to occur. The electrical charges and atmospheric conditions present in a thunderstorm contribute to the formation of lightning.
Conclusion:
- All of the given statements (A, B, and C) are true about lightning.

Introduction:
Lightning is a natural phenomenon that occurs during thunderstorms. It is a powerful discharge of electricity that occurs between clouds, or between a cloud and the ground. Lightning is accompanied by a brilliant flash of light and the sound of thunder. In this response, we will discuss the three statements given in the question and explain why all of them are true.

A) A brilliant flash of light is called a spark:
The statement is incorrect. A brilliant flash of light produced during a lightning strike is not called a spark. It is commonly referred to as a lightning bolt. A spark, on the other hand, is a small electrical discharge that occurs between two conductive objects with a potential difference.

B) A single flash of lightning is called a lightning bolt:
The statement is correct. A single flash of lightning is indeed called a lightning bolt. A lightning bolt is a visible discharge of electricity that occurs within a thunderstorm. It can travel between different clouds or from a cloud to the ground. Lightning bolts can vary in length, width, and intensity.

C) Lightning can lead up to a thunderstorm:
The statement is correct. Lightning is often associated with thunderstorms. Thunderstorms are large-scale weather systems characterized by the presence of thunder, lightning, heavy rain, strong winds, and sometimes hail. Lightning is a result of the atmospheric conditions within a thunderstorm, such as the buildup of electrical charges and the movement of air currents. Thus, lightning is a common occurrence during thunderstorms.

Conclusion:
In conclusion, all of the given statements are true about lightning. A brilliant flash of light during a lightning strike is called a lightning bolt, not a spark. Lightning is often associated with thunderstorms, as it is a result of the atmospheric conditions within a thunderstorm. Therefore, all three statements are correct.