Chemistry Chapter on Energy Levels and Bonding

Energy Levels

• Energy levels are represented by electron shells.
• Electrons can move between energy levels by gaining or losing energy equal to the difference between the levels.
• Atoms can absorb energy to move electrons to higher energy levels.
• Atoms can release energy to move electrons to lower energy levels.

Electron Configuration and Chemical Properties

• The chemical behavior of an atom is determined by its electron configuration and distribution.
• Valence electrons are those in the outermost shell.
• Valence electrons determine an atom's chemical behavior.
• Atoms tend to complete or empty partially filled valence shells, driving chemical reactions.

Chemical Bonding

• Covalent bonds involve the sharing of valence electrons between atoms.
• Molecules consist of two or more atoms held together by covalent bonds.
• A single bond is the sharing of one pair of valence electrons.
• A double bond is the sharing of two pairs of valence electrons.

Types of Covalent Bonds

• Non-polar covalent bonds involve equal sharing of electrons between atoms with identical electronegativity.
• Polar covalent bonds involve unequal sharing of electrons between atoms with different electronegativities.
• Polarity refers to the separation of charge into distinct positive and negative regions.

Electronegativity

• Electronegativity is an atom's attraction for electrons in a covalent bond.
• More electronegative atoms pull shared electrons more strongly towards themselves.
• In nonpolar covalent bonds, atoms have similar electronegativities and share electrons equally.
• In polar covalent bonds, atoms have different electronegativities and share electrons unequally.

Ionic Bonds

• Ionic bonds form when atoms transfer electrons, creating ions.
• Ions are charged atoms with more or fewer electrons than usual.
• Anions are negatively charged ions.
• Cations are positively charged ions.
• An ionic bond is the attraction between anions and cations.
• Ionic compounds are often called salts which may form crystals.

Weak Chemical Bonds

• Hydrogen bonds form when a hydrogen atom covalently bonded to one electronegative atom is attracted to another electronegative atom.
• Van der Waals interactions involve transient attractions between positive and negative regions of molecules.
• Weak chemical bonds reinforce the shapes of large molecules and help molecules adhere to each other.

Molecular Shape and Function

• Molecular shape determines how biological molecules recognize and respond to each other with specificity.
• Structure determines function.
• Molecular shape is determined by the positions of an atom's valence orbitals.
• s and p orbitals can hybridize, creating specific molecular shapes.

Chemical Reactions

• Chemical reactions involve the making and breaking of chemical bonds, leading to changes in the composition of matter.
• Chemical reactions convert reactants to products.

Chemical Equilibrium

• Chemical equilibrium is reached when the forward and reverse reaction rates are equal.

This quiz covers key concepts related to energy levels, electron configuration, and chemical bonding. It explores how electrons transition between energy levels and how valence electrons influence the chemical behavior of atoms. Additionally, it delves into the nature of covalent bonds and molecular formation.