Answer:
Na-O
Be-S
Explanation:
ionic bonds= metal and non metal
Answer: Potential energy is converted to kinetic energy and back again.
Explanation:At points 1 and 3, the pendulum stops moving, and its mechanical energy is purely potential. At point 2, the pendulum is moving the fastest, and its mechanical energy is purely kinetic. Therefore, as the pendulum moves from point 1 to point 3, its potential energy is first converted to kinetic energy, then back to potential.