Question

Which of the following statements is(are) correct? a. The symbols for the elements magnesium, aluminum, and xenon are \(\mathrm{Mn}, \mathrm{Al},\) and \(\mathrm{Xe},\) respectively. b. The elements \(\mathrm{P}\), As, and \(\mathrm{Bi}\) are in the same family on the periodic table. c. All of the following elements are expected to gain electrons to form ions in ionic compounds: \(\mathrm{Ga}, \mathrm{Se},\) and \(\mathrm{Br}\). d. The elements \(\mathrm{Co}, \mathrm{Ni},\) and \(\mathrm{Hg}\) are all transition elements. e. The correct name for \(\mathrm{TiO}_{2}\) is titanium dioxide.

Short answer

The correct statements are b, d, and e. Statement b is correct because P, As, and Bi are in the same family (the nitrogen family) on the periodic table. Statement d is correct because Co, Ni, and Hg are all transition elements. Statement e is correct because the name for TiO₂ is indeed titanium dioxide.

Step-by-step solution

Statement a: Element Symbols

The given statement says that the symbols for magnesium, aluminum, and xenon are Mn, Al, and Xe, respectively. The correct symbol for magnesium is Mg not Mn, which represents manganese. Therefore, this statement is incorrect.

Statement b: Element Families

The statement mentions that elements P (phosphorus), As (arsenic), and Bi (bismuth) are in the same family on the periodic table. These elements are in group 15, also known as the nitrogen family, on the periodic table. Thus, the statement is correct.

Statement c: Gain of Electrons

The statement discusses Ga (gallium), Se (selenium), and Br (bromine) gaining electrons to form ions in ionic compounds. Gallium is a metal and typically loses electrons (it forms a Ga³⁺ ion). Selenium and bromine are non-metals and gain electrons when forming ions (Se²⁻ and Br⁻ ions, respectively). Therefore, the statement is partially correct, but not entirely correct as all elements do not gain electrons.

Statement d: Transition Elements

The statement talks about Co (cobalt), Ni (nickel), and Hg (mercury) as transition elements. These elements are indeed transition elements, located in the d-block of the periodic table. Therefore, this statement is correct.

Statement e: Titanium Dioxide

The statement claims that the correct name for TiO₂ is titanium dioxide. This statement is correct. Titanium dioxide follows the ionic compound naming convention, and the name signifies one titanium atom bonded to two oxygen atoms in the compound. In conclusion, the correct statements are b, d, and e.

Key concepts

Element Symbols

Understanding element symbols is fundamental in chemistry. Each element on the periodic table is represented by a unique one or two-letter symbol. For example, magnesium is denoted by 'Mg,' not 'Mn,' which actually represents manganese. Elements like aluminum and xenon are correctly symbolized as 'Al' and 'Xe,' respectively.

In chemistry, precision is key, and using the incorrect element symbol can completely change the meaning of a chemical formula or equation. For instance, confusing 'Mg' (magnesium) with 'Mn' (manganese) could lead to misunderstandings about the element's properties, such as atomic mass, reactivity, and role in compounds. Therefore, knowing and using the correct element symbols is essential for studying and communicating in the field of chemistry.

Gain of Electrons

The process of gaining electrons during chemical reactions is a critical concept. When atoms gain electrons, they form negatively charged ions, also known as anions. This process is essential in the formation of ionic compounds. For example, selenium (Se) and bromine (Br) are nonmetals that tend to gain electrons and form anions Se²⁻ and Br⁻, respectively.

However, not all elements gain electrons; metals like gallium (Ga) usually lose electrons to form cations. Thus, it's important to note the type of element when predicting if it will gain or lose electrons. Understanding this aspect of electron transfer is crucial when predicting the charge of ions and when balancing chemical equations.

Transition Elements

Transition elements are metals located in the d-block of the periodic table, often referred to as the 'transition metals.' This group includes elements like cobalt (Co), nickel (Ni), and mercury (Hg). Transition metals are known for their ability to form compounds with variable oxidation states and their use as catalysts in various chemical reactions.

Characteristics such as d-orbital electrons, distinctive colored compounds, and magnetic properties set these elements apart from others. Students should be familiar with the defining traits of transition metals to understand their behavior during the formation of compounds and their applications in different fields of chemistry and materials science.

Ionic Compound Naming

The naming of ionic compounds follows specific rules that help in identifying the composition of the compound. For instance, 'titanium dioxide' signifies a compound consisting of one titanium atom and two oxygen atoms, represented by the formula TiO₂. The convention involves naming the metal (cation) first, followed by the nonmetal (anion), with the anion's ending changed to '-ide.'

In more complex compounds with transition metals capable of forming ions with various charges, Roman numerals are used to indicate the cation's positive charge. For example, FeCl₂ is named iron(II) chloride, while FeCl₃ is named iron(III) chloride. Understanding these rules is key for students to correctly name and write formulas for ionic compounds, a fundamental skill in chemistry.