The element that corresponds to the electron configuration 1 s^2 2s^2 2p^6 is Th

Question

The element that corresponds to the electron configuration 1 s^2 2s^2 2p^6 is The complete electron configuration of gallium, element 31, is Give the ground state electron configuration for Se. Which of the following have the same number of valence electrons? Which of the following sets of elements is in the incorrect order of increasing atomic radius (smallest one first, etc.)? Give the number of core electrons for O. Place the following in order of increasing electronegativity. Which is the ground stare electron configuration for Se^2+. In which of the following, elements are placed in order of decreasing metallic character correctly? What is the formal charge on nitrogen

Explanation / Answer

15)

given

1s2 2s2 2p6

total electrons = 2 + 2 + 6 = 10

the atomic number of 10 is neon

so

E. neon

16)

given atomic number 31

so

there are 31 electrons

the configuration is

1s2 2s2 2p6 3s2 3p6 3d10 4s2 2p3

so

the answer is option . B

17)

given selenium

the electron configuration is [Ar] 3d10 4s2 4p4

so

the answer is option A

18) elements with same number of valence electrons belong to the same group of periodic table

here

Rb, Sb , I are not in the same group

Ga, Sn , Bi are not in the same group

As , Sb , Bi are in the same group

Ar , Kr , Br are not in the same group

So

the answer is option C)

19)

we know that

atomic radius increases down the group

and

atomic radius deacreases along the period from left to right

so

using this information

the answer is E) I , Se ,S

here the order is decreasing

20)

the electron configuration of Oxygen is 1s2 2s2 2p4

outer electrons are 6

core electrons are 2

so

C) 2

21)

the answer is B) As < N < F

22) the conifugartion for Se is [Ar] 3d104s24p4

remove two electrons to get Se-2

so

[Ar] 3d10 4s2 4p2

answer is option B

23) metallic character decreases acorss the period form left to right

metallic character increases down the group

so

the answer is option E) K > As > P

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.