Charcoal from the dwelling level of the Lascaux Cave in France gives an average count of 0.97 disintegrations of C-14 per minute per gram of sample. Living wood gives 6.68 disintegrations per minute per gram. Estimate the date of occupation and hence the probable date of the wall painting in the Lascaux Cave. (Half-life of C-14 is 5568 years)

15502 years

Explanation:

From;

0.693/t1/2 = 2.303/t log [Ao]/[A]

Where;

t1/2 = half life of C-14

t = time taken

[Ao] = count rate of living sample

[A] = count rate of the charcoal under study.

0.693/5568 = 2.303/t log (6.68/ 0.97)

1.245 * 10^-4 = 2.303/t log (6.887)

1.245 * 10^-4  = 1.92998/t

t = 1.92998/1.245 * 10^-4

t = 15502 years

answer: mercury

explanation:

"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."