According to atomic theory:

a. the nucleus is positively charged.

b. the nucleus contains both charged and uncharged particles.

c. the electrons contribute very little to the total mass of the atom.

d. the electrons are located in the atomic space outside the nucleus.

e. all of these

e. all of these

Explanation:

Let us check all the given options one by one:

a. The nucleus is positively charged.

Yes it is correct since nucleus contain protons and neutrons and protons are positively charged.

b. The nucleus contains both charged and uncharged particles.

Yes because protons are positively charged and neutrons are neutral in nature.

c. The electrons contribute very little to the total mass of the atom.

Yes we know all the mass of the atom is considered in center and mass of electron is negligible as compared to protons and neutrons.

d. The electrons are located in the atomic space outside the nucleus.

Yes, its a known fact.

e. All of these.

Since, all given options are correct.

Therefore, option e. is right.