Andy has two samples of liquids. sample a has a ph of 4, and sample b has a ph of 6. what can andy conclude about these two samples?

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

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.

Which of the following has wavelength longer than the wavelength of viable light? a) x rays b) gamma rays c) radios waves d) ultraviolet waves