What Do You Know About The Halogens?

Explanation
Halogens are elements in Group 17 of the periodic table, also known as the halogen group. They have 7 valence electrons, which are the electrons in the outermost energy level of an atom. This is because halogens have 7 electrons in their outermost energy level, and they require only one more electron to achieve a stable electron configuration. Therefore, the correct answer is 7.

Explanation
Halogens are found on the right side of the periodic table. The periodic table is divided into several groups or families, and halogens belong to Group 17. They include elements such as fluorine, chlorine, bromine, iodine, and astatine. These elements are highly reactive and tend to form compounds with other elements. Being on the right side of the periodic table, halogens have a high electronegativity and readily gain an electron to achieve a stable electron configuration.

Explanation
Halogens can be easily found in the natural world in salt compounds with metals. Halogens, such as chlorine, fluorine, bromine, and iodine, have a high affinity for metals and often form compounds with them. These compounds are commonly found in nature, such as sodium chloride (table salt), potassium iodide, and calcium fluoride. Therefore, the correct answer is "In salt compounds with metals."

Explanation
All of the given terms are associated with halogens. Halogens are nonmetallic elements, meaning they lack the characteristics of metals. They are diatomic, meaning they exist as diatomic molecules (such as Cl2, Br2, etc.). Additionally, halogens are highly reactive elements due to their tendency to gain one electron to achieve a stable electron configuration. Therefore, none of the given terms are not associated with halogens.

Explanation
Fluorine is the lightest halogen because it has the lowest atomic mass among the given options. Halogens are a group of elements in the periodic table that include fluorine, bromine, iodine, chlorine, and others. Fluorine has an atomic mass of 19. It is followed by chlorine with an atomic mass of 35, bromine with an atomic mass of 80, and iodine with an atomic mass of 127. Therefore, fluorine is the lightest halogen among the options provided.

Explanation
Fluorine is the most reactive element in the entire periodic table because it has the highest electronegativity, meaning it has a strong attraction for electrons. This makes fluorine highly reactive and prone to forming chemical bonds with other elements. It readily accepts electrons to achieve a stable electron configuration, making it a powerful oxidizing agent. Fluorine can react vigorously with almost all other elements, including noble gases, and is known for its ability to react explosively with water and organic compounds.

Explanation
Bromine is a halogen that exists as a liquid at room temperature. Unlike the other halogens (iodine, astatine, and chlorine) which are typically gases or solids, bromine has a boiling point of 58.8 degrees Celsius, allowing it to remain in liquid form at normal room temperatures. This characteristic makes bromine unique among the halogens and is the reason why it is the correct answer to the question.

Explanation
Iodine is the correct answer because it is the only halogen that sublimates at room temperature. Sublimation is the process in which a substance transitions directly from a solid to a gas without going through the liquid state. Fluorine, chlorine, and astatine do not sublimate at room temperature, they either exist as gases (fluorine and chlorine) or solids (astatine) at room temperature. Therefore, Iodine is the only halogen that undergoes sublimation at room temperature.

Explanation
Fluorine is a gas at room temperature because it has a lower boiling point compared to the other halogens. Fluorine has a boiling point of -188.12°C, which is below room temperature, allowing it to exist as a gas under normal conditions. In contrast, iodine, bromine, and astatine are all in a liquid or solid state at room temperature.

Explanation
Astatine is the correct answer because it is the only halogen that is radioactive. Astatine is a highly unstable element with a very short half-life, making it difficult to study and obtain in large quantities. It is primarily produced through the decay of other elements and has limited practical applications. The other halogens, iodine, fluorine, and chlorine, are not radioactive and have various uses in industries and everyday life.