Listen Given the equation:
12(s) → 12(g)
Which phrase describes this change?
1.
endothermic chemical change
2.
endothermic physical change
3.
exothermic chemical change
4.
exothermic physical change

668900 atoms in total

No. an alpha particle is a pair of protons and a pair of neutrons, i.e. a helium

Vander waals forces are inter molecular bonds that exist within molecules of the same substance. a water molecule is made up of oxygen and hydrogen atoms which share electrons between each other. the vander waals forces are forces that exist between multitude of different  molecules of water. dipole dipole forces is the type of vander waals force that exist in water. the oxygen atom which is more electronegative pulls the shared electron closer to itself thus generating a partial negative charge while the hydrogen acquire a partial positive charge. these two different charges causes attraction to occur in water molecules.