The answer is A :) your welcome hope this helps
Answer:

Explanation:
We have the equation for ideal gas expressed as:
PV=nRT
Being:
P = Pressure
V = Volume
n = molar number
R = Universal gas constant
T = Temperature
From the statement of the problem I infer that we are looking to change the volume and the pressure, maintaining the temperature, so I can calculate the right side of the equation with the data of the initial condition of the gas:



So

Now, as for the final condition:


clearing



1. carbon lies in the 2nd period where silicon in the third period.
2. carbon is a non metal whereas silicon is a metalloid.
3. there are only 3 isotopes of carbon and 23 isotopes of silicon
4. size of silicon atom is larger
5. silicon is heavier than carbon.