Yes what the other person said can I plz get an thanks
I believe the answer is "After adding two substances together a new order is detected" because nearly all of the other answers suggest a chemical change has taken place. The reason I say "almost" is because answer two and four results in bubbles forming so the answer cannot be both. The only one to not clearly show a chemical change has occurred is the last answer.
We would most likely use a model for an atom, which shows the nucleus, particles, and the electrons + orbitals
Longer pendulums swing with a lower fequency than shorter pendulums. The force of gravity accelerates the pendulum down. The momentum built up by the acceleration of gravity causes the mass to swing in the opposite direction to a height equal to the original position. So therefore I think the answer your looking for is gravity.
Both mass and weight are measured by using scales.
