Answer:
In order to have a full outer shell atoms can GAIN or LOSE electrons. Atoms with very few VALENCE electrons, such as Lithium, would need to gain many electrons for a full shell so it is easier for them to LOSE electrons and become POSITIVE.
Explanation:
- I hope this helped!
Answer:

Explanation:
From the question we are told that:
1st Energy 
2nd Energy 
3rd Energy 
Generally the equation for Energy E for electron in one dimensional box at ground state
is mathematically given by


Therefore Length a is mathematically given as



We subtract the enthalpies of the reactants from that of the products:

Since this is < 0, this is an exothermic reaction.
The correct option is B.
Mendeleev was the one who originated the idea of arranging elements in the periodic table according to their chemical and physical properties. He left spaces in the periodic table and predicted the discovery of those elements that had not been discovered then. One of these elements is Gallium. He predicted that gallium is going to be a metal and he gave the properties that the element will possess. He also predicted that the element gallium will be placed under aluminium in the periodic table.