Question

How is the energy level of an atom's valence electrons related to its period in the periodic table?

Answer 1

Hint: We know that there is restriction in relationship but for nonmetallic transition metal that is non d block and non d block these are one. Meanwhile the valence electrons are usually listed and after here noble gas core within reason example is tungsten \[W\].

Complete step-by-step answer:
The energy level of an atom valence electron corresponds to its period as well as horizontal row on the periodic table. Hydrogen helium, both in the first period have their valence electrons in the principal energy level \[n=1\] The second period lithium through helium has outer electrons in the \[n=2\] level. These patterns continue. For main group elements which are thus in groups\[1A,2A,\text{ }3A,\text{ }8A~\] digit that goes with group number is also number of valence electrons. Group 1A elements have one valence electron \[Group\text{ }2A\] are \[2\] and so on.

Finding number as well as the energy level of valence electrons is more and more complicated transition metals. They have electrons in d-orbitals that are very close in energy to s-electrons of the next energy level. In fourth period \[K,\text{ }Ca\] have their valence electrons in \[4th\] energy level in \[4s\] sub level The transition metals following \[Sc,\text{ }Zn\] have outer electrons in \[4s\] and \[3d\] sublevel. Some form ions with charges higher than \[+2\] in which these are losing in the both 4s and \[3d\] electrons.

Note: Some heavy f block metals mainly lanthanides and actinides also have access to occupied \[\left( n-2 \right)f\] orbitals too and those electrons might also be included in their set of valence electrons they might even not have \[\left( n-1 \right)d\] valence electrons sometimes.