An ab4 molecule has two lone pairs of electrons on the a atom (in addition to the four b atoms). what is the electron-domain geometry around the a atom?

Answer : The electron-domain geometry around the 'A' atom is, octahedral.

Explanation :  

As per given in the question, an has two lone pairs of electrons on the atom 'A' and four number of monovalent atoms (B) are bonded to the central atom.

That means, the total number of electrons pairs = 2 + 4 = 6

The number of electrons pairs is 6 that means the hybridization will be and the electronic or electron domain geometry of the molecule will be octahedral.

The electron domain geometry is also shown below.

Hence, the electron-domain geometry around the 'A' atom is, octahedral.

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.

quartz

explanation: