CONCLUSION

Group I elements have similar physical and chemical properties since they all have one electron in their outermost energy level. Their reactivity also increase down the group since the ease to lose one electron increases down the group as the attractive force of the nucleus decreases. The ionic radii are smaller than the atomic radii since alkali metals form ions by loss of an electron. The remaining electrons are held more firmly hence the shrinking of the atom and hence a smaller ionic radius.