Answer:
1.65hr
Explanation:
Given parameters:
Number of labs = 5 labs
Time taken = 3 minutes
Unknown:
Time taken in hours to grade 165 labs = ?
Solution:
Let us find the rate of the teacher;
Rate = 
Insert the parameters and solve;
Rate = 
= 1.67labs/min
Now;
Time to grade 165 labs = 
Time to grade 165 labs = 
= 98.8min
Since;
60min = 1hr
98.8min = 
= 1.65hr
That is a chemical change.. Hope I helped!
Ca²⁺ion has a lower ratio of charge to volume.
The charge density of an ion is defined as the ratio of the charge of an ion to its volume. Scandium ion has high charge density than calcium ions. The charge density of an ion is defined as the ratio of the charge of an ion to its volume.
Charge density also depends on the size of the ion and valence electrons. The volume of an ion increases with its size. It is inversely proportional to ion volume and directly proportional to charge magnitude. Scandium and calcium are IV periodic elements with atomic numbers of 21 and 20 respectively. Scandium loses three electrons and has a +3 charge and calcium is a divalent cation. Hence, the Scandium ion has high charge density than the calcium ion.
Learn more about charge density here: brainly.com/question/12968377
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