Question

recall from yesterday that there are 4 subblocks (s, p, d, and f) that hold electrons. notice, the s block holds 2 electrons and is 2 elements wide, the p block holds 6 electrons and is 6 elements wide, the d block holds 10 electrons and is 10 elements wide, and the f block holds 14 electrons and is 14 electrons wide. an electron configuration is used to show how many electrons hang out in specific areas of an atom at specific time (because the bohr model is \wrong\ and the quantum model shows the actual shape of an atom based on its electrons and sub blocks). use your notes from yesterday to determine the electron configuration for the following elements. hint: try to pay attention to the patterns that you see. as a refresher, the electron configuration for nitrogen is 1s² 2s² 2p³ (this shows that it is in the second energy level/period, in the p sub block, and is the 3rd element. the 1s² 2s² that is before just shows the elements and sub blocks that we passed to get to nitrogen 1. beryllium 1s² 2s² 2. oxygen 3. magnesium 4. chlorine 5. calcium 6. iron

Explanation:

Step1: Recall electron - filling rules

Electrons fill sub - blocks in order of increasing energy: 1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p and so on. The s sub - block can hold 2 electrons, p can hold 6, d can hold 10 and f can hold 14.

Step2: Determine electron configuration of Oxygen

Oxygen has 8 electrons. The first 2 fill the 1s sub - block (1s²), the next 2 fill the 2s sub - block (2s²), and the remaining 4 fill the 2p sub - block (2p⁴). So the electron configuration is 1s²2s²2p⁴.

Step3: Determine electron configuration of Magnesium

Magnesium has 12 electrons. 2 electrons in 1s (1s²), 2 in 2s (2s²), 6 in 2p (2p⁶) and 2 in 3s (3s²). So the electron configuration is 1s²2s²2p⁶3s².

Step4: Determine electron configuration of Chlorine

Chlorine has 17 electrons. 2 in 1s (1s²), 2 in 2s (2s²), 6 in 2p (2p⁶), 2 in 3s (3s²) and 5 in 3p (3p⁵). So the electron configuration is 1s²2s²2p⁶3s²3p⁵.

Step5: Determine electron configuration of Calcium

Calcium has 20 electrons. 2 in 1s (1s²), 2 in 2s (2s²), 6 in 2p (2p⁶), 2 in 3s (3s²), 6 in 3p (3p⁶) and 2 in 4s (4s²). So the electron configuration is 1s²2s²2p⁶3s²3p⁶4s².

Step6: Determine electron configuration of Iron

Iron has 26 electrons. 2 in 1s (1s²), 2 in 2s (2s²), 6 in 2p (2p⁶), 2 in 3s (3s²), 6 in 3p (3p⁶), 2 in 4s (4s²) and 6 in 3d (3d⁶). So the electron configuration is 1s²2s²2p⁶3s²3p⁶4s²3d⁶.

Answer:

1. 1s²2s²2p⁴
2. 1s²2s²2p⁶3s²
3. 1s²2s²2p⁶3s²3p⁵
4. 1s²2s²2p⁶3s²3p⁶4s²
5. 1s²2s²2p⁶3s²3p⁶4s²3d⁶