Question

4.) the number of unpaired electrons in an atom can be determined from the filling diagrams and correctly applying hunds rule. boron has one unpaired electron, while carbon has two, and nitrogen has three. how many unpaired electrons does fluorine have? (1 point)
○ 1
○ 2
○ 5
○ 3

5.) how many unpaired electrons does calcium have? you may need to draw the orbital filling diagram for the last sublevel that contains electrons. (1 point)
○ 1
○ 0
○ 2
○ 4

Explanation:

Question 4

Step1: Recall Fluorine's Electron Configuration

Fluorine (F) has an atomic number of 9, so its electron configuration is $1s^2 2s^2 2p^5$.

Step2: Analyze the p - sublevel

The $2p$ sublevel has 3 orbitals. According to Hund's rule, electrons fill orbitals singly first. The $2p$ sublevel has 5 electrons. We fill the 3 orbitals with one electron each (3 electrons), then pair the remaining 2 electrons. So, there is 1 unpaired electron in the $2p$ sublevel.

Question 5

Step1: Recall Calcium's Electron Configuration

Calcium (Ca) has an atomic number of 20, so its electron configuration is $1s^2 2s^2 2p^6 3s^2 3p^6 4s^2$.

Step2: Analyze the last sublevel

The last sublevel with electrons is the $4s$ sublevel. The $4s$ sublevel has 1 orbital, and it contains 2 electrons, which means the orbital is completely filled (paired electrons). So, there are 0 unpaired electrons.

Answer:

A. 1