Answer:
hydrogen helium lithium berrylium boron carbon nitrogen
it small because that bond is not very polar notice that all of those arrows they cancel. because they point in opposite directions. that's why BH 3 is nonpolar if we were to draw the Lewis structure of bf3. ... so even though the boron fluorine bond is polar the molecule as a whole is nonpolar.
Larger gases produces more spectral lines than the smaller gases because they have more orbitals in their atoms.
Hydrogen has only one orbital in which an electron orbits. At the excited state, that is, when the electron gains energy, the number of energy level it can transcend is very few. For larger elements, they have more orbitals and when excited, they can move from the ground state to other energy levels at which they produce various unique spectral lines.
Sodium. It reacts with most of every other element.