Adding a conjunction to the sentence:

The school bell rang and the children rushed out.

Explanation:

Conjunctions are words that connect phrases, clauses, or sentences. They are used to show the relationship between these elements. In this case, the conjunction "and" is used to connect two independent clauses - "The school bell rang" and "the children rushed out".

Using "so" as a conjunction would also be grammatically correct, but it would change the meaning of the sentence slightly. "So" is used to indicate a cause-and-effect relationship between two clauses. For example, "The school bell rang, so the children rushed out" implies that the ringing of the bell caused the children to rush out.

Heading: Conjunctions

- Conjunctions connect phrases, clauses, or sentences
- They show the relationship between these elements

Heading: Using "and" as a conjunction

- "And" is used to connect two independent clauses
- It indicates that both clauses are of equal importance

Heading: Using "so" as a conjunction

- "So" is used to indicate a cause-and-effect relationship between two clauses
- It implies that the first clause caused the second clause.