Answer:
i think it's 3 because there aren't any indexes so that leaves us with one atom of Ca, one atom of O, and one atom of H
Answer:
the answer is most likely b, sorry if im wrong.
Explanation:
.....
A) iron melting is the only example of physical change, because it's just a change of state (from solid to liquid).
The others, rusting, combustion, and decay are all chemical changes, because it will result in changing the chemical bonds between the atoms.
Reflection, refraction, and diffraction
Reflection occurs when waves bounce back from a surface that they cannot pass through. Refraction occurs when waves bend as they enter a new medium at an angle and start traveling at a different speed.
