Question

1. how many electrons can each sublevel hold?

a. s=
b. p=
c. d=
d. f=

1. the s sublevel can hold ____ electrons at each energy level and the electrons have ____ spins (direction).
2. the lowest energy state of an atom is its ____________ state.
3. what is the element for the following electron configuration?

b. 1s²2s²2p⁶3s²3p³ ____________

1. what is the atomic number for the following electron configuration?

c. 1s²2s²2p⁶3s²3p⁶4s² ________

1. complete the orbital diagram for nickel (ni):

1s 2s 2p 3s 3p 4s 3d

1. complete the electron configuration for the following element:

d. magnesium ____________________

1. complete the noble gas notation for the following element:

e. selenium ____________________

Explanation:

Step1: Recall electron - holding capacity of sublevels

The s - sublevel has 1 orbital and each orbital can hold 2 electrons, so it can hold 2 electrons. The p - sublevel has 3 orbitals, and 3×2 = 6 electrons. The d - sublevel has 5 orbitals, and 5×2=10 electrons. The f - sublevel has 7 orbitals, and 7×2 = 14 electrons.
a. 2
b. 6
c. 10
d. 14

Step2: Answer question 12

The s sublevel can hold 2 electrons at each energy level. According to the Pauli - exclusion principle, the two electrons in the s orbital have opposite spins. So the blanks are 2 and opposite.

Step3: Recall atomic energy states

The lowest energy state of an atom is its ground state.

Step4: Determine element from electron configuration

For the electron configuration 1s²2s²2p⁶3s²3p³, the total number of electrons is 2 + 2+6 + 2+3=15. The element with atomic number 15 is phosphorus (P).

Step5: Find atomic number from electron configuration

For the electron configuration 1s²2s²2p⁶3s²3p⁶4s², the sum of electrons is 2+2 + 6+2+6+2 = 20. The atomic number is equal to the number of electrons in a neutral atom, so the atomic number is 20.

Step6: Draw orbital diagram for nickel (Ni)

Nickel has an atomic number of 28. Its electron configuration is 1s²2s²2p⁶3s²3p⁶4s²3d⁸.
1s: ↑↓
2s: ↑↓
2p: ↑↓ ↑↓ ↑↓
3s: ↑↓
3p: ↑↓ ↑↓ ↑↓
4s: ↑↓
3d: ↑↓ ↑↓ ↑↓ ↑ ↑

Step7: Write electron configuration for magnesium

Magnesium has an atomic number of 12. Its electron configuration is 1s²2s²2p⁶3s².

Step8: Write noble - gas notation for selenium

Selenium has an atomic number of 34. The nearest noble gas with a lower atomic number is argon (Ar, atomic number 18). So the noble - gas notation is [Ar]4s²3d¹⁰4p⁴.

Answer:

1. a. 2

b. 6
c. 10
d. 14

1. 2; opposite
2. ground
3. phosphorus (P)
4. 20
5. 1s: ↑↓

2s: ↑↓
2p: ↑↓ ↑↓ ↑↓
3s: ↑↓
3p: ↑↓ ↑↓ ↑↓
4s: ↑↓
3d: ↑↓ ↑↓ ↑↓ ↑ ↑

1. 1s²2s²2p⁶3s²
2. [Ar]4s²3d¹⁰4p⁴