What is a result of the unequal electron sharing in a water molecule?
a. water molecules have a nonpolar bond.
b. water molecules have a weakly positive oxygen end.
c. water molecules have a weakly positive hydrogen end.
d. water molecules have two oxygen and two hydrogen atoms

The right choice is  c. Water molecules have a weakly positive hydrogen end.

Explanation:

The unequal sharing of electrons in water molecule gives a slight negative charge near its oxygen atom ( see image below) and a slight positive charge near its hydrogen atoms. A neutral molecule that has a partial positive charge at one end and a partial negative charge at the other, it is a polar molecule.

so

a. Water molecules have a nonpolar bond.

It is wrong choice because water has polar bond .

b. Water molecules have a weakly positive oxygen end.  

Also, a wrong choice due to water molecule gives a slight negative charge near its oxygen atom.

c. Water molecules have a weakly positive hydrogen end.  

This is the right choice.

d. Water molecules have two oxygen and two hydrogen atoms

It is wrong choice because water has one oxygen and two hydrogen atoms

So, the right choice is

c. Water molecules have a weakly positive hydrogen end.  

the electrical  conductivity  of asolution  of an electrolyte is measured by determining the resistance of thesolution  between two flat or cylindrical electrodes separated by a fixed distance.

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.