Answer: Hydrogen bonds
Explanation: Hydrogen bonds allow two molecules to link together temporarily. Water molecules are made up of two hydrogen atoms and one oxygen atom, held together by polar covalent bonds.
Answer:
Many years ago, people living on the Earth, desired to go to the outer space.
Explanation:
When man initiate to go outer space:
Many times ago, people used to think about the world out of Earth, the space and the sky. These thoughts generated the idea of thinking and imagining the space and the moon.
The idea turned into a movie by Georges Méliès, which was inspired by a book written by Jules Verne. The movie gave the idea to Konstantin Tsiolkovsky, a Russian man to develop many ideas which were implemented by Russia and America to build airplanes and rockets that we see launching at present.
A small though became an idea which gave birth to a new invention through which people live their dreams of going in the outer space. Incredible!
The heat used in phase changes is calculated by multiplying the mass of the substance by the energy of the phase change. In this case, for liquid to boil, we would find total heat by multiply the mass of liquid by the latent heat of vaporization (Hvap). If we are instead given the Hvap and the total heat of 1 kJ, we would divide 1 kJ by the Hvap (which is usually in kJ/kg) to get the mass of liquid boiled (in kg).
