Please state the options and I will answer to the best of my abilities XD
Answer:
A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.
It should be at about 65J. Not sure, hope I helped.
B
paired electrons spin in opposite directions cancelling their magnetic fields