<span>Quantum mechanic model is based on mathematics. As per this theory the exact position and momentum of electron is impossible to understand. It uses complex shapes of orbitals called electron clouds. n describes the energy of an electron. Larger the value of n larger the distance of electron from the nucleus and larger the orbital. l describles the shape of orbital. Orbitals having same of value of n and different values for l are called subshells.</span>
⭐ 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 .
Answer:
Mass = 20 g
Explanation:
Given data:
Number of moles of He = 5 mol
Mass of He = ?
Solution:
Formula:
Number of moles = mass/ molar mass
Molar mass = 4 g/mol
by putting values,
5 mol = Mass / 4 g/mol
Mass = 5 mol × 4 g/mol
Mass = 20 g
Answer:
FBr is a chemical formula representing "flourine monobromide."
Explanation:
Of course, FBR could represent a number of things, from the Federal Board of Revenue to a fluidized bed reactor. I gave the answer I did because you listed this question as Chemisty.