Answer:
Charge= -2.
Gains two electron into the 4p^4 to become 4p^6.
Explanation:
The element in the periodic table/chart that matches with the valence electron configuration is Selenium with full electron configuration of [Ar] 3d^10 4s^2 4P^4 which is a non-metal that is found in group 4 of the periodic table/chart.
Selenium can receive 2 more electrons on the 4p^4 to give a -2(minus 2) ion that is Se^2-.
Selenium can also loose 2 electron from 4s^2 to give a +2 ion that is Se^2+.
Selenium can also loose 2 electrons from 4s^2 and 2 electrons from 4p^4 to form Se^4+.
Selenium can also loose 2 electrons from 4s^2 and 4 electrons from 4p^4 to form Se^6+.
Thus, in order to form a monatomic ion with a charge(we will be making use of the most stable one). Thus, it will gain two more electron since this is easier to become 4s^2 4p^6.
Mass of water : 0.45 g
<h3>Further explanation</h3>
Given
1.5 g ethanoic acid
Required
Mass of water
Solution
Reaction
<em>CH₃COOH + NaOH ⇒H₂O + CH₃COONa</em>
mol CH₃COOH(MW=60 g/mol) :
= mass : MW
= 1.5 : 60
= 0.025
mol H₂O from the equation :
= 0.025(mol ratio CH₃COOH : H₂O= 1 : 1)
Mass of water :
= mol x MW water
= 0.025 x 18 g/mol
= 0.45 g
The attraction of inter-molecular forces between molecules is defined by a general term "Van der Waals forces". It is the weak interactions caused by momentary changes in electron density in a molecule.
Inter-molecular forces that are present between hydrogen atom which is bonded to highly electronegative atom (
) and the lone pair electrons present in the other molecule on these electronegative atoms is known as hydrogen bonding.
The type of interactions between methane, 
is Van der Waals interactions whereas in water, 
is hydrogen bonding.
Since, the hydrogen bond is stronger than the Van der Waals forces so, it results in higher strength between the molecule possessing hydrogen bonding. Thus, molecules possessing hydrogen bonds will have higher boiling point than the molecules which possess Van der Waals forces.
Hence, water () have a significantly higher boiling point than methane ( ) because water molecules are attracted to one another by hydrogen bonds.
