Answer:
HF
Explanation:
This concept can be understood from the knowledge of Intermolecular forces of attraction.
Intermolecular bonds are Van der Waals forces which are weak forces of attraction joining non-polar and polar molecules together. They exist in the form of London Dispersion Forces and Dipole-dipole attraction.
An example of Dipole-dipole attraction is the hydrogen bond which is a unique dipole-dipole attraction between polar molecules in which a hydrogen atom is directly joined to a highly electronegative atom such as fluorine, oxygen, or nitrogen).
Molecules that possess the characteristics of hydrogen bonding have a higher boiling point. In the given question, only HF undergo hydrogen bond due to the electronegative effect of the fluorine element.
F2 occurs as a weak London dispersion force and it occurs between non-polar molecules.
Unicellular organisms, cells perform all the basic actions and functions required for living like nutrition, respiration, reproduction etc.
In multicellular organisms, cells divide their tasks on the basis of "DIVISION OF LABOUR" to specialize in certain functions besides respiration etc. Like conduction in neurons, excitation in muscles, RBC production by bone marrow etc.
Steam is made from boiling things and water vapor is from boiling water.
Temperature and pressure are directly proportional. Pressure will also have to increase ( doubling).