Is mending a broken bone chemical change and why(short answer pls)

The volume of an unknown substance in a sealed glass jar is 50 milliliters. the volume of the jar is 200 milliliters. which state of matter could the substance be?

What is the empirical formula of a compound that is 50.7% antimony and 49.3% selenium ?

You are attempting to recrystallize a crude product mixture. you add the appropriate amount of hot solvent and are allowing the solution to slowly cool to room temperature. however, at room temperature no crystals have appeared, which of the following methods should be used to induce crystallization? choose all correct answers. a) place the flask in an ice bath. b) swirl the contents of the flask. c) add a small seed crystal of the desired product. d) scratch the inside of the glassware using a stir rod. it can be multiple choices