These types of reactions are called endothermic reactions. This is when the system absorbs the heat from the surrounding. In this case, the system is the chemical reaction and the environment is the direct vicinity of the chemical reaction. You notice that the pack becomes cold because heat from the surrounding is being absorb.
The bonds involved in this substance includes ionic bonding and polar covalent.
Answer:
2H2 + O2 -----> 2H2O
Not sure about the second question though.
<em>Answer: The disasters are different according to their occurrence. For example, the causes of an earthquake cannot be the same as that of forest-fire. Natural disasters are caused due to different reasons like soil erosion, seismic activity, tectonic movements, air pressure, and ocean currents etc.</em>
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<em>Explanation: Have a great day,</em>
Digestive. This also includes the intestines.