Stephen Kiprotich, the 2012 Olympic marathon winner, completed the 26.219 miles in 128 minutes. What was his speed in kilometers per minute? What steps should you take to solve this problem?

Explanation:

To begin, we can divide the number of miles by the number of minutes: 26.219/128 = 0.205 miles per minute. Next, we can use the proper conversion factor to give the number of kilometers per minute. Since 1 mile = 1.609 km, we can divide 0.205/1.609 to result in 0.127 kilometers per minute.

"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."