Which of the following is a buffer system? Which of the following is a buffer system? H2CO3(aq) and KHCO3(aq) NaCl(aq) and NaOH(aq) H2O(l) and HCl(aq) HCl(aq) and NaOH(aq) NaCl(aq) and NaNO3(aq)

Explanation:

A buffer is defined as an aqueous mixture of a weak acid and its conjugate base or vice versa.

In the systems:

H₂CO₃(aq) and KHCO₃(aq): Carbonic acid, H₂CO₃, is a weak acid that, in solution with its conjugate pair, HCO₃⁻ make a buffer system.

NaCl(aq) and NaOH(aq): NaCl is a salt and NaOH is a strong base. Thus, this system is not a buffer system.

H₂O(l) and HCl(aq): Water is a solvent and HCl a strong acid. This is not a buffer system.

HCl(aq) and NaOH(aq): HCl is a strong acid and NaOH a strong base. This is not a buffer system.

NaCl(aq) and NaNO₃(aq): Both NaCl and NaNO₃ are salts and this system is not a buffer system.

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

the solar system used to have much dust particles option no d