Final answer:
In soccer, if the ball crosses the goal line before the horn sounds to end the half, the goal would count.
Step-by-step explanation:
In this situation, it would depend on the rules of the game. Generally, in soccer, if the horn sounds to end the half at the same time the ball is crossing the goal line, the goal would count. This is because the completion of the action, which is the ball crossing the goal line, occurred before the end of the half. However, it's important to note that different leagues or organizations may have slightly different rules regarding timing of goals.