The two dry sand samples are examined by changing one parameter. The independent variable, the one that is intentionally manipulated between the two samples, is the .

Besides the amount of material, there is also another variable that is manipulated within each of the two mass groups and represented as three types. This independent variable is the
.

In each case, the dependent variable, the one that you measure the response in, is the
.

the first box is correct

The two dry sand samples are examined by changing one parameter. The independent variable, the one that is intentionally manipulated between the two samples, is the  Mass of each sample

the second box as well

Besides the amount of material, there is also another variable that is manipulated within each of the two mass groups and represented as three types. This independent variable is the type of material used

& the third box

In each case, the dependent variable, the one that you measure the response in, is the temperature over time

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.

it is stable as it is in group 0 which have full outer shells of electrons