How many covalent bonds are formed by each atom in the following molecules? Draw molecules using the electron-dot-symbols and lines to show the covalent bonds. a. PH₃ b. H₂Se c. HCl d. SiF₄

Verified step by step guidance

1. Identify the central atom in each molecule: PH₃ (P), H₂Se (Se), HCl (Cl), SiF₄ (Si).
2. Determine the number of valence electrons for each central atom: P has 5, Se has 6, Cl has 7, Si has 4.
3. Draw the electron-dot symbols for each molecule, showing the valence electrons around the central atom.
4. Connect the central atom to surrounding atoms (H, F) using lines to represent covalent bonds, ensuring each atom achieves a stable electron configuration.
5. Count the number of covalent bonds formed by each central atom: PH₃ (3 bonds), H₂Se (2 bonds), HCl (1 bond), SiF₄ (4 bonds).

Key Concepts

Covalent Bonds

Covalent bonds are formed when two atoms share one or more pairs of electrons. This type of bond typically occurs between nonmetals and is crucial for the formation of molecules. The number of covalent bonds an atom can form is determined by its valence electrons, which are the electrons in the outermost shell that participate in bonding.

Lewis Dot Structures

Lewis dot structures are diagrams that represent the valence electrons of atoms within a molecule. They use dots to show individual electrons and lines to represent covalent bonds between atoms. This visual representation helps in understanding how atoms bond and the arrangement of electrons, which is essential for predicting molecular geometry and reactivity.

Molecular Geometry

Molecular geometry refers to the three-dimensional arrangement of atoms in a molecule. It is influenced by the number of covalent bonds and lone pairs of electrons around the central atom. Understanding molecular geometry is important for predicting the physical and chemical properties of substances, including polarity, reactivity, and phase of matter.