The principal quantum number of the valence electrons in a atom of lead is
A. 2
B. 3
C. 4
D. 5
E. 6
The principal quantum number corresponds to the number of the element's period. Lead is in the sixth period, so its quantum number is 6.
The energy level of the valence electrons of every element is the same as its period in the periodic table.
So in this case Lead = 6 (E.)
To determine the principal quantum number of the valence electrons in an atom of lead, we need to know the electron configuration of lead.
The electron configuration of lead (Pb) is [Xe] 4f14 5d10 6s2 6p2.
The valence electrons of an atom are the electrons in the outermost energy level. In the case of lead, the outermost energy level is the sixth energy level (n=6). Thus, the principal quantum number of the valence electrons in a lead atom is 6.
Therefore, the correct answer is E. 6.
To determine the principal quantum number of the valence electrons in an atom of lead, we need to know the electron configuration of lead.
Lead (Pb) has an atomic number of 82, which means it has 82 electrons. The electron configuration of lead is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p².
The valence electrons are the electrons in the highest energy level, which in this case is the 6p² level.
The principal quantum number (n) refers to the energy level of an electron. In this case, the valence electrons are in the n=6 energy level.
Therefore, the answer is E. 6.