I believe it is either A. or C. my guess is A.
Answer: The new pressure of the gas in Pa is 388462
Explanation:
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,

where,
= initial pressure of gas at STP = 
= final pressure of gas = ?
= initial volume of gas = 700.0 ml
= final volume of gas = 200.0 ml
= initial temperature of gas = 273 K
= final temperature of gas = 
Now put all the given values in the above equation, we get:


The new pressure of the gas in Pa is 388462
Lithium i believe is the answer
Answer: Matter cannot be created or destroyed
Explanation: Balanced equations are set equations we cannot change one element or compound in the equation without changing the entire equation. So balanced equation show the conservation of mass because while other substances may be formed from the synthesis or decomposition of compounds new elements are never introduced and are not created out of thin air :)
As the temperature of a liquid increases, its viscosity decreases.