Black hole, or a singularity contained within an event horizon through which no light can escape.

⭐ Elements in which the last electron enters any one of the five d-oribitals of their respective penultimate shells are called as <u>d-block</u><u> </u><u>elem</u><u>ents</u> .
⭐ But the last electron of Zn , Cd , Hg and Cn enters in the s-oribital of their respective ultimate shells rather than the d-oribitals of their respective penultimate shells . Therefore, these elements cannot be regarded as d-block elements .
☃️ But properties of these elements resemble to the d-block elements rather than s-block elements .
☃️ Therefore, to make the study of periodic classification of elements more rational, they are studied along with d-block elements .
✍️ Thus <u>on the basis of properties</u> all transition elements are d- block elements, but <u>on the basis of electronic configuration</u> all d -block elements are not transition elements .
Hi there!
We can use pythagorean theorem to solve this problem here. The easiest way to go about solving this problem is to use the theorem to find the hypotenuse, then dividing it by 5 to find the value of x, since the hypotenuse is 5x.
WORK:
27^2 + 36^2 = h^2 (plugging into theorem)
729 + 1296 = h^2 (squaring the numbers)
h^2 = 2025 (adding the numbers together)
hypotenuse = 49 (taking the square root of 2025)
49/5 = x (dividing 49 by 5 to find x)
x = 9.8 (dividing)
Hope this helps!! :)
If there's anything else that I can help you with, please let me know!