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Over [174]
3 years ago
13

Which element has four energy levels? Na,K,Cs,Rb

Chemistry
2 answers:
Ann [662]3 years ago
7 0
Potassium K 

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Alik [6]3 years ago
6 0

Answer:

The correct option is: Potassium

Explanation:

Sodium, Potassium, Rubidium and Caesium are referred to as the alkali metals that belong to the group 1 of the periodic table, thus having one valence electron in their outer or valence shell.

Sodium, atomic number 11, belongs to the period 3 of the periodic table. It has <u>three shells</u> and the number of electrons per shell is 2, 8, 1.

Potassium, atomic number 19, belongs to the period 4 of the periodic table. It has <u>four shells</u> and the number of electrons per shell is 2, 8, 8, 1.

Rubidium, atomic number 37, belongs to the period 5 of the periodic table. It has <u>five shells</u> and the number of electrons per shell is 2, 8, 18, 8, 1.

Caesium, atomic number 37, belongs to the period 6 of the periodic table. It has <u>six shells</u> and the number of electrons per shell is 2, 8, 18, 18, 8, 1.

<u>Therefore, </u><u>Potassium</u><u>, atomic number 19, has four shells or energy levels.</u>

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First we will calculate free energy change:
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n = 2 (given by equation that the electrons involved is 2)
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E⁰ = (698 x 1000) / (2 x 96485) = 3.62 volts   
 
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