Is matter conserved when there is the same amount before and after a change?

The answer is b because a,c,and d are opinons

The answer is c.  h+  and oh−  react to form water (h2o). i just took the test and i got it right. hope this !

The surface of the water droplet is held together by the attraction between molecules. in order for water to flow more easily into these small spaces, you need to decrease its surface tension. you can do this by adding soap, which is a surfactant (a material that decreases the surface tension of a liquid).