<span>There is a direct correlation between the period number and the energy level for valence electrons. For example, the H and He elements, in period 1, have their outer electrons in the energy level "1". This continues down the rows: all the elements in period 2 have their principal energy level as n = 2, period 3 has n = 3, and so on.</span>
The nonpolar end of a soap molecule attaches itself to grease.
HNO3 + Ca —-> H2O + N20 + Ca(NO3)2
Phosphorus is in group 15 meaning it have 5 valence electrons. This means that it needs 3 more electrons to create a full outer shell. As these three electrons are negatively charged it means that P is a 3- ion (it’s an anion [negatively charged ion])
The arrangement of atoms within a molecule is called molecular structure. It <span> is the three-dimensional arrangement of the atoms that constitute a </span>molecule<span>. It determines several properties of a substance. Hope this answers the question. Have a nice day.</span>
