Question

An unknown element is a nonmetal and has a valence electron configuration of \(n s^{2} n p^{4}\). a. How many valence electrons does this element have? b. What are some possible identities for this element? c. What is the formula of the compound this element would form with potassium? d. Would this element have a larger or smaller radius than barium? e. Would this element have a greater or smaller ionization energy than fluorine?

Short answer

a. This element has 6 valence electrons. b. The possible identities for this element are Oxygen, Sulfur, Selenium, Tellurium, and Polonium. c. The formula of the compound this element would form with potassium is K2X. d. This element has a smaller radius than barium. e. This element has a smaller ionization energy than fluorine.

Step-by-step solution

Determine the number of valence electrons

From the given electron configuration \(n s^{2} n p^{4}\), we can count the number of valence electrons the element has. There are 2 electrons in the "s" orbital and 4 electrons in the "p" orbital, making a total of 2 + 4 = 6 valence electrons. a. This element has 6 valence electrons.

Identify the possible element

Since the element has 6 valence electrons and is a nonmetal, it falls under Group 16 (also known as Chalcogens) in the periodic table. Some possible elements in Group 16 include: - Oxygen (O) - Sulfur (S) - Selenium (Se) - Tellurium (Te) - Polonium (Po) b. The possible identities for this element are Oxygen, Sulfur, Selenium, Tellurium, and Polonium.

Determine the formula for the compound with potassium

Since the element has 6 valence electrons, it requires 2 more electrons to achieve a stable octet. Potassium (K) has 1 valence electron and readily loses this electron to form a positive ion, K⁺. Therefore, the unknown element will gain 2 electrons and form a negative ion with a 2- charge. It takes two potassium ions (K⁺) to balance the charge of the nonmetal ion (X²⁻), where 'X' represents our nonmetal element. So, the formula of the compound this nonmetal element forms with potassium will be K2X. c. The formula of the compound this element would form with potassium is K2X.

Compare the radius of the element with barium

Barium (Ba) is an alkaline earth metal and is located in Group 2 of the periodic table and has a bigger atomic size. The unknown nonmetal is in Group 16 and has a smaller atomic size. As we go across a period from left to right, atomic size decreases, and therefore, this nonmetal element will have a smaller radius than barium. d. This element has a smaller radius than barium.

Compare the ionization energy with fluorine

Fluorine (F) is located in Group 17 of the periodic table and has the highest ionization energy of all elements in the same period. Since the unknown nonmetal element is in Group 16, it will have a lower ionization energy than fluorine because ionization energy decreases as we go from right to left in the periodic table. e. This element has a smaller ionization energy than fluorine.