The charges on an ion signifies the number of electrons that has been lost, gained or shared by an atom. These electrons are called valence electrons occupying the outermost shell of an atom.
Group 1A element will readily be willing to lose an electron giving them a charge of +1
Group 3A can lose either 1 or 3 electrons giving a charge of +3 or +1
Group 5A can lose either 5 or 3 electrons giving a charge of +5 or +3
The number of lost electron confers the stability on the configuration.
No, because plastic cups can be dissolved by organic compounds. Moreover, they are easily melted so a highly exothermic reaction can not be studied using them.
