Answer:
The tank with O₂ weighs more.
Explanation:
We can find the mass of gas using the ideal gas equation.

Considering the pressure (P), volume (V), temperature (T) and ideal gas constant (R) are the same, we can establish that:
m ∝ M
The mass is directly proportional to the molar mass. The molar mass of O₂ (32 g/mol) is higher than the molar mass of N₂ (28 g/mol). Therefore, the tank with O₂ weighs more.
Answer: The reaction is exothermic. The value of q is -542 kJ.
Explanation:
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and for the reaction comes out to be positive.
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and for the reaction comes out to be negative.
Thus
evolves heat , it is exothermic in nature. The value of q is -542kJ.
If the element has a charge of +2 it has lost two electrons giving it an overall positive charge making it a cation. In order to find the number of electrons, take the elements atomic number and subtract two since it lost two electrons
I would say B but I am not sure so sorry if it is wrong!!