In combustion energy is released so it is an exothermic process !!
the answer is 2nd one !!
It lowers density thats why its able too float :)
a lung is NOT an organism.
Adding because evaporation speed is increased with increased temperature
The atomic number is the number of protons in the nucleus of an atom. The number of protons define the identity of an element (i.e., an element with 6 protons is a carbon atom, no matter how many neutrons may be present).