In an exothermic reaction, the water will increase in temperature in a calorimeter. An exothermic reaction is a reaction where heat is one of the products or heat is being released from it which will cause for the temperature inside the calorimeter to increase.
B) Mg is the alkaline earth metal w/12 protons so following the periodic table to the halogen in the same period is
Cl: Chlorine
C) The Neutral noble has w/ 18 electrons is argon so the metal in the same row is
Na: Sodium
The question is incomplete, here is a complete question.
An arctic weather balloon is filled with 27.8 L of helium gas inside a prep shed. The temperature inside the shed is 13 ⁰C. The balloon is then taken outside, where the temperature is -9 ⁰C. Calculate the new volume of the balloon. You may assume the pressure on the balloon stays constant at exactly 1 atm. Be sure your answer has the correct number of significant digits.
Answer : The new volume of the balloon is 25.7 L
Explanation :
Charles's Law : It is defined as the volume of the gas is directly proportional to the temperature of the gas at constant pressure and number of moles.

or,

where,
= initial volume of gas = 27.8 L
= final volume of gas = ?
= initial temperature of gas = 
= final temperature of gas = 
Now put all the given values in the above equation, we get:


Therefore, the new volume of the balloon is 25.7 L
Periodic table is arranged according to atomic size and other properties.
Answer:
Your answer has to be B. Camouflage
Explanation: