Answer: Heat\pressure control
Explanation: In order to create metamorphic rock, it is vital that the existing rock remain solid and not melt. If there is too much heat or pressure, the rock will melt and become magma.
Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
The best example of how electromagnetic energy is used in everyday life is <span>a patient receiving an X-ray in a hospital</span>
Na22 and Na24 are isotopes
Answer : The value of 
for the reaction is +571.6 kJ/mole.
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given chemical reaction is,
Now we have to determine the value of for the following reaction i.e,
According to the Hess’s law, if we reverse the reaction then the sign of change.
So, the value 
for the reaction will be:
Hence, the value of for the reaction is +571.6 kJ/mole.
Multiply the mass by the abundance and add each. Make sure to convert the percentage into a decimal. (49.946 * .043) + (51.941 * .838) + (52.941 * .095) + (53.939 * .024) = 51.99 round up using sig figs and the answer is c. 52.00 amu
