Which involves a chemical change? 1.separating hydrogen and oxygen from water

2.evaporating sugar from sweetened water

3.filtering sand from water

4.distilling pure water from salt water

Which are examples of how technology has advanced scientific understanding.1using hot water to sterilize medical equipment.2transplanting a human organ into another individual.3inserting genes from one sheep into another cell to make a cloneunderstanding the different structures that make up a cell.4examining microorganisms from the deepest parts of the ocean