The most significant property of an apple that would be different on the Moon compared to Earth is its weight.

Here's why:

* Gravity: The Moon has significantly less gravity than Earth (about 1/6th). This means an apple on the Moon would weigh six times less than on Earth.

* Weight vs. Mass: It's important to remember that the apple's mass (the amount of matter it contains) remains the same. It's the force of gravity that determines its weight.

So, while an apple's mass wouldn't change, its weight would be drastically different on the Moon.