Some things that can indicate a chemical change are change of odor, change of color, change in temperature or energy, such as the production or loss of heat. An example could be the rusting of metal, there would be a color change of going from a shiny silver to a dirty, splotchy red color. Some things that indicate a physical change are change of appearance like change of shape, etc. It can also be like a change between a solid to liquid to gas. For example, the cutting of a piece of paper.
<span>19.992*0.9048+20.993*0.0027+21.991+0.0925 = </span><span> 20.1797 amu (C)</span>
The chemical formula for magnesium sulfate is MgSO4, so it shows that there are four atoms of oxygen but not sulfur. There is only one atom of sulfur in the formula
You could use a scale to measure the mass as well as a cup to hold the water. If you were comparing the two, you should also probably use a graduated cylinder to get the same amount of each type of water.
Hope this helped ^_^
