If the proton number increases while the number of energy levels remains constant, what happens to the attractive force between the nucleus and the electrons? How does your answer to the previous question explain the trend in radii across a period?

Its strengthits conductivity of heat and electricity its shiny colourmalleable and ductility

Van der waals forces are temporary electromagnetic forces established between uncharged atoms. some neutral molecules, when close together, can become temporarily “charged,” as electrons move around the atom. water is a polar molecule, the side of the molecule that the hydrogens bond to being more positive, and the opposite side bound to the lone pairs of electrons being more negative. this means that it participates in dipole-dipole interaction (non-polar exhibits dispersion forces), and it has the capacity for hydrogen bonding.