Chemistry Chapter 7 Quiz

Atomic Structure

• An atom is the smallest unit of matter forming a chemical element.
• Atoms are composed of a nucleus and one or more electrons.
• The nucleus contains protons and neutrons.
• Protons have a positive charge; electrons have a negative charge; neutrons have no charge.
• The number of protons defines the atomic number of an element.
• The number of protons plus neutrons is the mass number.
• Atoms with the same number of protons but different numbers of neutrons are isotopes.
• Ions are atoms or groups of atoms with a net positive or negative charge due to loss or gain of electrons.

The Periodic Table

• The periodic table organizes elements based on their atomic number and properties.
• Elements with similar properties are grouped together.
• Elements are classified into metals, nonmetals, and metalloids.
• Elements also categorized into groups (vertical columns).

Electron Configuration

• Electrons fill atomic orbitals following rules: Aufbau principle, Pauli exclusion principle, Hund’s rule.
• The arrangement of electrons in an atom's orbitals is its electron configuration.
• The different types of orbitals: s, p, d and f.
• Each principle energy level corresponds to a certain orbital.

Periodic Table Trends

• Atomic radius generally increases going down a group and decreases going across a period.
• Ionization energy generally increases going across a period and decreases going down a group.
• Electronegativity generally increases going across a period and decreases going down a group.
• Electron affinity generally increases going across a period and decreases going down a group.
• Effective nuclear charge generally increases going across a period.

Types of Chemical Bonds

• Ionic bonds: Occur between atoms with large differences in electronegativity. One atom loses electrons to become a cation, while another gains electrons to become an anion.
• Covalent bonds: Occur when atoms share electrons to achieve a stable electron configuration.
• Hydrogen bonds: A special type of dipole-dipole interaction occurring between a hydrogen atom bonded to a highly electronegative atom (N, O, or F) and an electronegative atom in a different molecule.
• Van der Waals forces: Weak intermolecular forces resulting from temporary fluctuations in electron distribution.
• Metallic bonds: Occur between metal atoms, where valence electrons are delocalized and shared among many atoms.

Chemical Forces

• Intramolecular forces: Strong forces that hold atoms together within a molecule.
• Intermolecular forces: Weak forces that exist between molecules.

Chemical Nomenclature

• Chemical nomenclature is the systematic naming of chemical compounds.
• Ionic compounds are named by stating the cation followed by the anion.
• Molecular compounds are named by using prefixes to indicate the number of each element.

Naming Oxoacids and Oxoanions

• systematic naming of oxygen-containing acids and their conjugate bases.
• The naming scheme differentiates between -ic and -ous in acid names, and the corresponding -ate or -ite suffixes in the names of oxoanions (conjugate base of oxoacids).

Elements and their Properties

• Specific elements (e.g., alkali metals, alkaline earth metals, halogens, noble gases) have characteristic properties that influence their behavior.
• All elements have unique properties defining their behaviors and interaction with other elements and molecules.

Isotopes

• Different forms of the same element which have the same number of protons but are different in the number of electrons.

Formulae/Models

• Different ways of representing chemical compounds (e.g., molecular formula, structural formula, ball-and-stick model).
• Chemical formulae and models aid in picturing the shape of the molecules and their constituent atoms.

Orbital Hybridisation

• Hybridization of atomic orbitals occurs when atoms bond to form molecules.
• Hybridization involves mixing atomic orbitals of comparable energies to produce new orbitals (hybrid orbitals).
• Different types of hybridization (e.g., sp³, sp², sp) lead to unique molecular shapes and bonding patterns.

Molecular Shapes

• Different molecular shapes (e.g., linear, bent, tetrahedral, trigonal planar) result from different bonding arrangements.
• The arrangement of atoms in a molecule impacts its physical and chemical properties.

Polarity

• A molecule's dipole moment is a measure of its overall polarity.
• It is influenced by the differences in electronegativity between bonded atoms.
• Polar molecules exhibit net dipole moments due to an uneven distribution of charge.

Boiling Point

• The boiling point is the temperature where the vapor pressure of a liquid equals the surrounding pressure.
• Varied by surrounding pressure and different properties of various compounds.

Melting point

• The melting point is the temperature at which a solid changes state to liquid.
• Affected by surrounding pressure.

Solubility

• Solubility refers to how much of a substance (solute) can dissolve in another substance (solvent).
• Factors affecting solubility include temperature, pressure, and chemical properties.

Paramagnetism and Diamagnetism

• Paramagnetic materials are weakly attracted to magnetic fields due to the presence of unpaired electrons.
• Diamagnetic materials are weakly repelled by magnetic fields due to all paired electrons.

Definitions of Some Terms

• Several terms are defined to aid in understanding different chemical behaviours and compounds.