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Determine the valence electron/s and predict the period and group number of the following elements by electron configuration. Provide evidence by showing work properly. Use a sheet of paper to do your work.

1. Silicon 2. Xenon 3. Barium 4. Potassium 5. Iodine

User Orlp
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1 Answer

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The location of an element can be estimated from its electron configuration

Further explanation

We can divide the periodic system into several parts:

1. Block s: groups 1 and 2 (having a configuration of 1s-7s) consist of active metals except for H (non-metals) and He (noble gases)

2. Block p: group 13-18 (has a 2p-6p configuration), also called a representative element because it includes metals, non-metals and metalloids

3. Block d: group 3-12 (having the 3d-6d configuration), are transition metal elements

4. Block f: Lanthanides and Actinides (having a 4f-5f configuration), are inner transition elements that are also metal

group⇒valence electron

period⇒the greatest value of the quantum number n

1. Silicon

electron configuration : [Ne] 3s²3p²

valence electron = 4(2+2), block p : group 14

period = n = 3

2. Xenon

electron configuration : [Kr] 4d¹⁰5s²5p⁶

valence electron = 8(2=6),block p : group 18

period = n = 5

3. Barium

electron configuration : [Xe] 6s²

valence electron = 2, block s, group 2

period = n = 6

4. Potassium

electron configuration : [Ar] 4s¹

valence electron = 1, block s, group 1

period = n = 4

5. Iodine

electron configuration : [Kr] 4d¹⁰5s²5p⁵

valence electron = 7(2+5), block p, group 17

period = n = 5

User Cwallenpoole
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