If you need to design a technological solution to lack of water availability in a developing country, which of the following should you do before proposing a solution? invest the money to test your most promising design select the best of several possible designs build a model to test research scientific principles involved in water availability

Anwser:

Research scientific principles involved in water availability.

Explanation:

Before building or investment you always want to see and know what your up against and what the best way to help or solve is. Researching why there's a problem in water availability or/and the principals to water availability will help you see what the problem is with what's happening to and around the process and it's environment.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

the answer is 1 i believe