Which of the following best describes the practice of slavery at the time of the Dred Scott case?

Slavery had expanded extensively across the continent, which made Northerners extremely nervous.

Slavery had been banned almost everywhere, which made Southerners extremely nervous.

There was a great deal of tension between the North and South over the practice of slavery.

The North and South remained in agreement about the Missouri Compromise, which had settled the slavery issue.

"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 ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface.

c) should be the answer.