Which of the following explains how one of the postulates in John Dalton's atomic theory was later subjected to change? Various scientists found that all atoms of a particular element are identical.
Some scientists found that atoms combine in simple whole number ratios to form compounds.
Various scientists found that atoms consist of subatomic particles with varying mass and charge.
Some scientists found that bonds between atoms are broken, rearranged, or reformed during reactions.

"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."

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b