1 point There are 118 known elements. How many elements have atoms, in their ground-state, with core electrons whose quantum numbers are n

The question is incomplete; the complete question is;

There are 118 known elements. How many elements have atoms, in their ground state, with core electrons whose quantum numbers are n=3 and l=1?

a. 10

b. 6

c. 100

d. 18

c. 100

Explanation:

If we look closely at the periodic table, we will notice that there 100 elements that occur after argon whose electronic configuration is; 1s2 2s2 2p6 3s2 3p6.

This means that there every other element after argon must have a 3p sublevel as part of its core electrons. In the 3p sublevel, n=3 and l=1.

If we diligently count the number of elements from potassium (immediately after argon) to Oganesson (element 118) we have a total of 100 elements all having core electrons of quantum numbers are n=3 and l=1.

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.