Arranges the following molecules in order of increasing dipole moment:
H2O, H2S, H2Te, H2Se.

Explanation:

Dipole moment is defined as the measurement of the separation of two opposite electrical charges.

is a bent shaped molecule with a dipole moment of 1.87.

is also a bent shaped molecule with a dipole moment of 1.10.

is a also a bent shaped molecule and has a negligible dipole moment.

has a dipole moment of 0.29.

Therefore, given molecules are arranged according to their increasing dipole moment as follows.

        < < <

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.