Outcome (dependent) variable-drinking energy drinks
Test (independent) variable- more aggressive
1) The metal which reduces the other compound is the one higher in the reactivity. So in this case it is 
.
2) The substance which brings about reduction while itself getting oxidised (that is losing electrons) is called a reducing agent. Here, $\mathrm{Zn}$ is the reducing agent and reduces Cobalt Oxide to Cobalt while itself getting oxidised to Zinc oxide.
Test tubes, spot and/or well plate will be used to combine substances in bottles and form a reaction is referred to a true statement.
<h3>What is a Chemical reaction?</h3>
This is the reaction which involves substances known as reactants combining new substances which are referred to as products. This is usually done in the laboratory and equipment and tools such as test tubes, thermometer etc are used.
Test tubes, spot and/or well plate are often used to combine substances in bottles and form a reaction which must be handled with care to ensure it doesn't spill.
This is therefore the reason why the option true was chosen as the most appropriate choice.
Read more about Chemical reaction here brainly.com/question/11231920
#SPJ1
IV: type of liquid used to water the plant (coca-cola, lemonade, water)
DV: height of growth
Control: time grown, same temperature and location
