Question

questions do a, c, e 2. predict the electron configuration of each of the following atoms. (a) _6c (b)
(c) _7n^+ (d)
(e) _20ca^2+

1. identify the neutral element from the electron configurations given (a) ne4s^2 3d^8 (b) kr5s^2 4d^10

valence, core and outer electrons
resource • flowers, p. et al. (2022). chapter 6.1 in chemistry 2e. openstax. <https://openstax.org/details/books/chemistry-2e>
video • electron configuration: (part 9 of 12) – inner, outer, and valence electrons. running time: 4:16 min. produced by moof university. <https://youtu.be/l-es6tkwt9q> • valence electrons and the periodic table. running time: 16:52 min. produced by tyler dewitt. <https://youtu.be/yadrwdntwec>
questions 4. define valence electrons.
x provide the number of valence, core, and outer electrons for the following atoms.

atoms

number of valence electrons

number of core electrons

number of outer electrons

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_6c

_51sb

_23v

_27co

Explanation:

Question 2(a): Predict electron configuration of \( _6\text{C} \)

Step 1: Determine atomic number

Carbon has atomic number 6, so 6 electrons.

Step 2: Apply Aufbau principle

Fill orbitals: \( 1s^2 \) (2 e⁻), \( 2s^2 \) (next 2 e⁻), remaining 2 e⁻ in \( 2p \): \( 2p^2 \).

Step 1: Find electrons in \( \text{N}^{3+} \)

Nitrogen (Z=7) loses 3 e⁻, so 7 - 3 = 4 e⁻.

Step 2: Fill orbitals

\( 1s^2 \) (2 e⁻), \( 2s^2 \) (remaining 2 e⁻).

Step 1: Electrons in \( \text{Ca}^{2+} \)

Calcium (Z=20) loses 2 e⁻, so 20 - 2 = 18 e⁻.

Step 2: Noble gas configuration

18 e⁻ match argon (Ar): \( [\text{Ar}] \) or \( 1s^2 2s^2 2p^6 3s^2 3p^6 \).

Answer:

\( 1s^2 2s^2 2p^2 \)

Question 2(c): Predict electron configuration of \( _7\text{N}^{3+} \)