1. 140 students participated in a knowledge retrieval session. 25 scored 90 out of 100; 63 scored 80 out of 100; 31 scored 70 out of 100; 15 scored 60 out of 100: 6 scored 50 on the
knowledge retrieval session. Determine the average score on this knowledge retrieval
session. Show all work.

76.14

Explanation:

The average will be the sum of all the marks that the students scored out of a hundred divided by the number of students.

25 scored 90

63 scored 80

31 scored 70

15 scored 60

6 scored 50

all the mentioned marks are out of hundred

Thus the average is given by

The average score of the students is 76.14.

"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."