Question

According to valence bond theory, how many bonds would you expect each of the following atoms (in the ground state) to form: Be, C?

Short answer

Be forms 2 bonds, C forms 4 bonds.

Step-by-step solution

Understand Valence Bond Theory Basics

According to valence bond theory, atoms form bonds by overlapping their atomic orbitals to achieve a more stable electron configuration, often resembling the nearest noble gas configuration within a molecule. The number of bonds an atom can form depends on its available valence electrons.

Determine Valence Electrons for Be

Beryllium (Be) is located in Group 2 of the periodic table, which means it has two valence electrons. Valence electrons are electrons in the outermost shell that can participate in bond formation.

Analyze Be Bonding Capacity

With two valence electrons, beryllium can share each one of these electrons with other atoms to form bonds. Thus, Be typically forms two covalent bonds, one for each of its valence electrons.

Determine Valence Electrons for C

Carbon (C) is located in Group 14 of the periodic table and has four valence electrons. These electrons occupy the outermost shell of the carbon atom.

Analyze C Bonding Capacity

Carbon tends to form four bonds, using one electron to share in each bond. This results in carbon achieving a stable configuration similar to that of neon. Carbon's unique ability to form four bonds allows it to create a vast array of complex molecules.

Key concepts

chemical bonding

Chemical bonding is a fascinating concept that describes how atoms come together to form molecules and compounds. It is the process through which atoms interact and stick together by sharing or transferring electrons to achieve stability. This is crucial because atoms in their isolated state generally lack stability.

Valence bond theory, one of the significant theories explaining chemical bonding, suggests that chemical bonds form when atomic orbitals overlap. These overlaps allow atoms to share electrons, resulting in a stable bond. The primary reason atoms bond is to achieve a configuration similar to noble gases, which are known for their stability.

• Atoms combine by either sharing electrons (covalent bonds) or transferring them (ionic bonds).
• The resulting compounds are more stable than the separate atoms.
• Bonding arrangements determine the chemical and physical properties of the compound.

By understanding chemical bonding, we can explain how complex structures are formed and how different materials are held together at the molecular level.

valence electrons

Valence electrons play a pivotal role in chemical reactions and bonding. They are the outermost electrons of an atom, residing in the highest energy level. These electrons are responsible for the chemical properties of the element because they can be gained, lost, or shared in bonding processes.

Knowing the number of valence electrons helps us predict an atom's typical bonding behavior. For instance, elements in Group 1 of the periodic table have one valence electron, making them highly reactive and eager to lose that electron to achieve stability. Conversely, elements in Group 18 are noble gases with a full set of valence electrons and are generally unreactive.

• Valence electrons determine an element's reactivity and bonding capacity.
• The periodic table helps us identify the number of valence electrons by group number.
• Electron dot structures visually represent valence electrons around atoms.

Understanding valence electrons provides insight into how elements interact, form bonds, and ultimately create the diverse types of matter we see around us.

covalent bonds

Covalent bonds form when two atoms share one or more pairs of valence electrons. This type of bonding is typical among nonmetals and is fundamental to many organic and inorganic compounds.

Unlike ionic bonds, which involve the transfer of electrons from one atom to another, covalent bonds result in electron sharing, creating a strong link between the bonded atoms. This type of bond leads to the creation of molecules such as water ( H_2O ) and methane ( CH_4 ).

• Covalent bonds can be single, double, or triple, depending on how many electron pairs are shared.
• The strength of a covalent bond is influenced by the overlap of atomic orbitals.
• Molecules with covalent bonds often have specific three-dimensional shapes essential for their functions.

Covalent bonds are crucial in biological systems, as they make up the backbone of proteins, DNA, and other key biomolecules.

atom stability

Atoms strive for stability, often resembling noble gases due to their full valence electron shells. This is the driving force behind the formation of chemical bonds. When atoms form bonds, they move towards achieving this ideal state of stability, reducing their potential energy.

Atom stability is primarily gained through full valence electron shells, usually following the "octet rule" where atoms aim to have eight electrons in their outer shell.

• Noble gases naturally possess filled valence shells, making them exceptionally stable and unreactive.
• Atoms of other elements form bonds to achieve a filled outer shell, similar to that of noble gases.
• Stable atoms tend to have lower energy, forming more durable bonds and stable compounds.

A deeper understanding of atom stability helps us delve into why certain chemical reactions occur and why particular molecular structures are possible. It is the core motivation behind bonding, shaping the whole chemistry of compounds.