Question

Name two halogens. Look up each of your choices in a dictionary, in a book such as The Handbook of Chemistry and Physics, or on the Internet, and make a list of their properties. Also list any uses of each element that are given by the source.

Short answer

Two halogens are chlorine and iodine. Chlorine is used in disinfectants, while iodine is used in medical treatments and iodized salt.

Step-by-step solution

Identify Halogens

The halogens are a group of elements found in Group 17 of the periodic table. These include fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). For this exercise, let's choose chlorine and iodine.

Research Chlorine

Consult a reliable source such as The Handbook of Chemistry and Physics or an online scientific encyclopedia to gather information on chlorine. Chlorine (Cl) is a greenish-yellow gas at room temperature with a pungent odor. It has an atomic number of 17 and an atomic mass of approximately 35.45 amu. Its electron configuration is [Ne] 3s² 3p⁵. One of the primary uses of chlorine is in water purification and the production of disinfectants and PVC (polyvinyl chloride).

Research Iodine

Look up iodine in your chosen source. Iodine (I) is a solid at room temperature, appearing as a dark-gray to purple-black lustrous material. It has an atomic number of 53 and an atomic mass of about 126.90 amu. Its electron configuration is [Kr] 4d¹⁰ 5s² 5p⁵. Iodine is used in the medical field as an antiseptic and in the treatment of thyroid conditions because it is an essential component of thyroid hormones. It's also used in iodized salt to prevent iodine deficiency.

Key concepts

Chlorine

Chlorine is a fascinating and versatile element found in Group 17 of the periodic table, which is known as the halogens. At room temperature, chlorine is a greenish-yellow gas with a distinct and strong odor. It has an atomic number of 17, which means it has 17 protons, and it typically has an atomic mass of about 35.45 atomic mass units (amu). In terms of electron configuration, chlorine is arranged with the electrons as [Ne] 3s² 3p⁵, meaning it has one electron shy of a full p-orbital, making it quite reactive.

Chlorine is widely known for its role in water purification. It is used to disinfect water, killing harmful bacteria and making it safe for drinking. Another important use of chlorine is in the production of various household and industrial chemicals, such as PVC (polyvinyl chloride), which is a type of plastic used in pipes, cable insulation, and clothing.

Moreover, chlorine is utilized in the manufacture of bleach, cleaning agents, and disinfectants, showcasing its versatility and essential role in modern life. It is crucial in maintaining hygiene and sanitation across numerous applications.

Iodine

Iodine is another intriguing member of the halogen family, occupying the 53rd position on the periodic table. Unlike chlorine, iodine is typically found as a solid at room temperature. It presents itself as a dark-gray to purple-black, lustrous material. With an atomic number of 53, iodine contains 53 protons and possesses an atomic mass of around 126.90 amu. Its electron configuration is [Kr] 4d¹⁰ 5s² 5p⁵, and like chlorine, iodine is eager to complete its p-orbital.

In the medical field, iodine is of significant importance. It serves as an effective antiseptic, making it a common inclusion in wound cleaning products. This element is also integral to the production of thyroid hormones, which regulate numerous vital processes in the body. Hence, it is pivotal in treating and managing thyroid-related conditions.

Additionally, iodine is routinely added to salt to produce iodized salt. This practice helps to prevent iodine deficiency, which can lead to health issues such as goiter and hypothyroidism. By ensuring adequate iodine intake through iodized salt, public health is significantly improved.

Chemical Properties

The chemical properties of halogens like chlorine and iodine make them highly reactive and excellent candidates for a variety of applications. These elements typically exist in nature as diatomic molecules, meaning two atoms form a stable molecule, such as Cl₂ or I₂. At the atomic level, the electron configurations of halogens are just one electron short of having a full valence shell, leading to high electronegativity and reactivity.

Chlorine and iodine both participate in oxidation-reduction reactions. Chlorine, being more electronegative, aggressively oxidizes other elements and compounds, often forming ionic or covalent bonds as it captures an electron to complete its valence shell.

Iodine, while also reactive, is less so compared to chlorine. It is more likely to form lower energy bonds, participating in chemical reactions at a slower rate. Nevertheless, due to their reactive nature, halogens are effective in various chemical reactions, such as bleaching, disinfection, and even organic synthesis, where they introduce or substitute functional groups.

Element Uses

Both chlorine and iodine find applications across a wide spectrum of uses, highlighting their importance in everyday life and industry.

• Chlorine Uses:
• Water Purification – Chlorine is used extensively to disinfect water and ensure a clean supply for drinking and swimming pools.


• Production of PVC – As a major component in PVC manufacturing, chlorine contributes to the creation of durable and weather-resistant plastic products.


• Bleaching and Disinfecting – Chlorine is key in producing bleaching agents and disinfectants, crucial for household and industrial cleaning.

• Iodine Uses:
• Antiseptics – Iodine is significant in medical antiseptics, helping to prevent infection in wounds.


• Thyroid Health – It is essential for producing thyroid hormones, making iodine crucial in treating thyroid disorders.


• Iodized Salt – This common dietary addition helps prevent iodine deficiency, supporting overall health.

From sanitation and health to industrial production, these halogens demonstrate a vast array of uses that enhance quality of life across the globe.