Question

Captain Kirk has set a trap for the Klingons who are threatening an innocent planet. He has sent small groups of fighter rockets to sites that are invisible to Klingon radar and put a decoy in the open. He calls this the "fishhook" strategy. Mr. Spock has sent a coded message to the chemists on the fighters to tell the ships what to do next. The outline of the message is Fill in the blanks of the message using the following clues. (1) Symbol of the halogen whose hydride has the second highest boiling point in the series of HX compounds that are hydrogen halides. (2) Symbol of the halogen that is the only hydrogen halide, HX, that is a weak acid in aqueous solution. (3) Symbol of the element whose existence on the sun was known before its existence on the earth was discovered. (4) The Group \(5 \mathrm{A}\) ( 15 ) element in Table \(19-13\) that should have the most metallic character. (5) Symbol of the Group \(6 \mathrm{A}(16)\) element that, like selenium, is a semiconductor. (6) Symbol for the element known in rhombic and monoclinic forms. (7) Symbol for the element that exists as diatomic molecules in a yellow-green gas when not combined with another element. (8) Symbol for the most abundant element in and near the earth's crust. (9) Symbol for the element that seems to give some protection against cancer when a diet rich in this element is consumed.(10) Symbol for the smallest noble gas that forms compounds with fluorine having the general formula \(\mathrm{AF}_{2}\) and \(\mathrm{AF}_{4}\) (reverse the symbol and split the letters as shown). (11) Symbol for the toxic element that, like phosphorus and antimony, forms tetrameric molecules when uncombined with other elements (split the letters of the symbol as shown). (12) Symbol for the element that occurs as an inert component of air but is a very prominent part of fertilizers and explosives.

Short answer

The filled-in message with the identified elements is: I, F, He, Bi, Te, S, Cl, O, Se, Xe, As, N.

Step-by-step solution

1. Halogen with second highest boiling point

The halogen series consists of Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (At). The boiling points of the hydrogen halides increase in the order HF < HCl < HBr < HI. Therefore, the second highest boiling point is HI, and the symbol for the corresponding halogen is I (Iodine).

2. Weak acid halogen

Among the hydrogen halides, HF is a weak acid. Thus, the symbol for the halogen that is a weak acid in aqueous solution is F (Fluorine).

3. Element known on the sun before Earth

The element that was discovered on the Sun before it was found on Earth is Helium. Its symbol is He.

4. Most metallic Group 5A element

Group 5A includes Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb), and Bismuth (Bi). The most metallic element in this group is Bismuth (Bi).

5. Semiconductor Group 6A element

Group 6A consists of Oxygen (O), Sulfur (S), Selenium (Se), Tellurium (Te), and Polonium (Po). The element that is a semiconductor like selenium is Tellurium (Te).

6. Rhombic and monoclinic forms

Sulfur (S) is an element that exists in rhombic and monoclinic forms.

7. Yellow-green diatomic gas

Chlorine (Cl) is a halogen that exists as diatomic molecules in a yellow-green gas when not combined with another element.

8. Most abundant element near the Earth's crust

Oxygen (O) is the most abundant element in and near the Earth's crust.

9. Cancer-protective element

Selenium (Se) is the element that seems to give some protection against cancer when a diet rich in this element is consumed.

10. Smallest noble gas forming compounds with F

Xenon (Xe) is the noble gas that forms compounds with fluorine having the general formulae \(\mathrm{XeF}_{2}\) and \(\mathrm{XeF}_{4}\).

11. Toxic element forming tetrameric molecules

Arsenic (As) is the toxic element that, like phosphorus and antimony, forms tetrameric molecules when uncombined with other elements.

12. Inert component of air in fertilizers and explosives

Nitrogen (N) is an inert component of air and is a crucial part of fertilizers and explosives. The message should now be filled in with the following symbols: I, F, He, Bi, Te, S, Cl, O, Se, Xe, As, N.

Key concepts

Halogens

Halogens are a unique group of elements located in Group 17 of the periodic table. They include Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (At). These elements are known for their high reactivity, especially when it comes to forming salts when they react with metals. For instance, table salt is formed by the reaction of sodium with chlorine. The reactivity of halogens decreases down the group; thus, Fluorine is the most reactive, while Astatine is the least.
One interesting property of the halogens is their different states at room temperature. Fluorine and chlorine are gases, bromine is a liquid, and iodine and astatine are solids. This variation occurs due to the increasing strength of van der Waals forces as you move down the group.
Halogens also play crucial roles in various chemical reactions and have significant uses in industries. For example, chlorine is used for water purification and in the production of various household products.

Element Symbols

Element symbols are shorthand notations used to represent chemical elements. They usually consist of one or two letters where the first letter is always capitalized, and the second, if present, is lowercase. For example, the symbol for hydrogen is H, while the symbol for helium is He. These symbols are derived from either the English name of the element or their Latin name. For instance, the symbol for gold is Au, short for 'Aurum,' its Latin name.
Using element symbols provides a consistent and universal way for scientists to communicate about elements and their reactions. These symbols are a key component of chemical equations, which describe how elements react and combine with each other.

Metallic Character

Metallic character refers to how easily an element can lose electrons, which is a typical property of metals. This characteristic tends to increase as you move down a group in the periodic table and decrease as you move from left to right across a period. Key factors affecting metallic character include atomic size, ionization energy, and electron affinity. Generally, elements on the left-hand side of the periodic table exhibit more metallic character.
Metals, known for their conductive properties, flexibility, and strength, often exist in the solid state at room temperature and exhibit characteristics such as luster and high melting and boiling points. Examples include Bismuth (Bi) from Group 5A, which is the most metallic in its group, showcasing these properties.

Semiconductors

Semiconductors are materials with electrical conductivity between that of a conductor and an insulator. Group 6A elements such as Selenium (Se) and Tellurium (Te) are known for their semiconductor properties. They play vital roles in electronics, especially in the manufacture of components like diodes, transistors, and solar cells.
Semiconductors can conduct electricity under certain conditions, making them essential for electronic devices that require controlled electrical flow. The ability to alter their conductivity through the addition of impurities, a process known as doping, makes them versatile and essential in modern technology. As they may be both elements or compounds, semiconductors are crucial in advancing technological applications.

Noble Gases

Noble gases are found in Group 18 of the periodic table and include elements like Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn). Known for their lack of reactivity, noble gases typically do not form compounds under standard conditions due to their complete valence electron shells.
Despite being chemically inert, some noble gases, like Xenon, have been found to form compounds under specific conditions. Xenon's unique ability allows it to bond with highly electronegative elements like Fluorine, forming compounds such as xenon difluoride ( Xef_2 ) and xenon tetrafluoride ( Xef_4 ). Additionally, noble gases are utilized in various applications: Helium is used in balloons and cooling systems, while Argon is often used in light bulbs and as an inert shielding gas in welding.