chemistry help please

Question

1. When dealing with the noble gases on the periodic table, they do not bond due to full valence shells. What is the correlation of the gaseous state and the lack of bonding?

 

2. How many electrons is an atom of sulfur likely to gain if an ionic bond i formed with a metal? How can you determine this?

Thanks!

Answer 1

1. Noble gases have full valence shells and therefore do not make bonds with other elements or with atoms of each other.  Therefore, they exist as single atoms, and not molecules. The only intermolecular forces they have are very weak London dispersion forces, which are very low for small, nonpolar atoms.  This would make them tend to be gaseous at room temperature.

 

2. Sulfur is in Group 6A on the periodic table of the elements.  Therefore it has 6 valence electrons.  In order to fill its valence shell, it needs 2 more electrons.  By directly adding 2 electrons, the S atom will become S^2- ion. 

 

NOTE: If S is covalently bonding to other atoms, it often wants to make 2 covalent bonds in order to obtain that same full valence shell.  However, since S is on Energy Level 3, it has available d-orbitals and can form an "expanded octet". So sometimes S makes more than 2 bonds.  ;)