Why do your legs appear shorter when standing in water

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

Maya wrote if you step to describe how carbon circulates between the atmosphere and living organisms

If a particle has z = 25 and 23 electrons, what is its charge?