Galileo was the first scientist to measure speed as distance over time.
Physical changes happen when you do/mix something that can be reversed. Best example is ripping a paper, you can just tape it back together so it is just an observable thing that changes, which is a physical change. Chemical changes happen when you mix things and they make a new substance and can’t be reversed. The best example of this is the Statue of Liberty, which changed in color due to the chemical change between the oxygen and copper, which created a new substance (rust) which made it green instead of copper.
Sorry for the long answer but hope this helps!
Answer:
An impurity is something that ruins the uncontaminated nature of something. If someone accuses you of impurity, they think you or your nature has been spoiled in some way by sin. When water is pure, the only thing in that water is water.
The classic Periodic Table<span> organizes the chemical </span>elements<span> according to the </span>number of<span> protons that each has in its atomic nucleus. Hope this helped :)</span>
