Write a balanced equation for the reaction of elemental boron with each of the following (most of these reactions require high temperature): (a) \(\mathrm{F}_{2}\) (b) \(\mathrm{O}_{2}\) (c) S (d) Se (e) \(\mathrm{Br}_{2}\)

A chemical reaction is a process where substances, known as reactants, transform into new substances called products. The transformation occurs as atoms are rearranged through the breaking and forming of chemical bonds. In the case of elemental boron reacting with different substances such as fluorine, oxygen, sulfur, selenium, and bromine, we see various chemical reactions taking place. Each of these reactions involves boron combining with another element to form a compound.

For example, when boron reacts with fluorine (F2) under high temperatures, it forms boron trifluoride (BF3). Each of these reactions requires a precise balance for the reactants to fully convert to products without leaving any leftover atoms, adhering to the Law of Conservation of Mass which states that matter is neither created nor destroyed in chemical reactions.

Stoichiometry is a branch of chemistry that deals with the quantitative relationships between reactants and products in a chemical reaction. It is based on the balanced chemical equation, which shows the proportion of reactants needed to form a specific amount of product. When balancing equations, such as those involving boron's reactions, we use stoichiometry to determine the coefficients that make the number of atoms of each element equal on both sides of the equation.

To improve students' understanding, it's crucial to highlight the role of coefficients in stoichiometry. They are the numbers placed in front of chemical formulas to indicate the ratio in which substances react and are produced. For instance, in the reaction of boron with oxygen to form boron trioxide \(B2O3\), the coefficient 4 in front of B and 3 in front of \(O2\) ensures that there are 8 boron atoms and 6 oxygen atoms on both sides of the equation, maintaining mass balance.

Chemical compounds are substances composed of two or more different types of atoms chemically bonded together. In the reactions provided, boron forms various chemical compounds with each of the elements it reacts with. For example, with fluorine, it forms boron trifluoride (BF3); with oxygen, boron trioxide \(B2O3\); with sulfur, boron sulfide \(B2S3\); with selenium, boron selenide \(B2Se3\); and with bromine, boron tribromide (BBr3).

These compounds have specific chemical and physical properties, including molecular structure, boiling and melting points, reactivity, and more, which are determined by the types of atoms involved and how they are bonded. Understanding the formula of a compound is crucial as it reveals the ratio of each type of atom within the compound, which is fundamental when navigating through chemical equations and stoichiometry.