Can someone help me with this please???

Procedure:
Please be sure to identify the test variable (independent variable) and the outcome variable (dependent variable) for this investigation. Remember, the test variable is what is changing in this investigation. The outcome variable is what you are measuring in this investigation.
Test variable (independent variable):

Outcome variable (dependent variable):

The factor that is different between the control and experimental groups is known as independent variable. The value you measure during the experiment and what is affected is known as dependent variable.  

Explanation:

The variable is independent because it does not depend on what happens in the experiment. The variable that depends on independent variable is dependent variable.

The condition that exist in different amounts and types are tested using test variables. Independent variables are marked as x-axis and dependent variable as y-axis.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.