Atomic Structure and Periodic Table Quiz

Atomic Structure

• Atoms are the fundamental building blocks of matter, composed of a nucleus containing protons and neutrons, surrounded by orbiting electrons.
• Protons carry a positive charge, neutrons are neutral, and electrons carry a negative charge.
• The number of protons in an atom determines its atomic number and its identity as an element.
• Isotopes are atoms of the same element with different numbers of neutrons, thus different atomic masses.
• Electron configuration describes the arrangement of electrons in various energy levels and sublevels around the nucleus.
• Electron shells (principal quantum numbers) represent energy levels, and subshells (s, p, d, f) indicate the shape of the electron orbitals.

Periodic Table

• The periodic table organizes elements based on their atomic number and recurring chemical properties.
• Elements are arranged in rows (periods) and columns (groups).
• Elements within a group exhibit similar chemical properties due to similar valence electron configurations.
• Elements are classified as metals, nonmetals, and metalloids based on their properties.
• Metals are generally good conductors of heat and electricity, while nonmetals are generally poor conductors. Metalloids exhibit properties intermediate between metals and nonmetals.

Bonding

• Chemical bonds hold atoms together in molecules and compounds.
• Ionic bonds form between a metal and a nonmetal, involving the transfer of electrons from the metal to the nonmetal, forming ions with opposite charges which attract each other.
• Covalent bonds form between nonmetals, involving the sharing of electrons between atoms.
• Metallic bonds result from the delocalization of electrons among metal atoms, allowing for strong attraction and conductivity.
• Intermolecular forces are attractive forces between molecules, including hydrogen bonds, dipole-dipole interactions, and London dispersion forces.

Chemical Reactions

• Chemical reactions involve the rearrangement of atoms to form new substances.
• Reactants are the substances that undergo change, and products are the substances formed.
• A chemical equation represents a chemical reaction, showing the reactants and products and their relative amounts.
• Chemical reactions are classified based on the type of changes occurring, including synthesis, decomposition, single displacement, double displacement, and combustion reactions.
• Stoichiometry is the study of the quantitative relationships between reactants and products in chemical reactions.

States of Matter

• Matter exists in three primary states: solid, liquid, and gas.
• Solids have a fixed shape and volume, liquids have a fixed volume but take the shape of their container, and gases have neither a fixed shape nor volume, filling the container they occupy.
• Changes of state occur when energy is added or removed from a substance, altering its kinetic energy.
• Phase diagrams are a graphical representation of the phases of a substance at different temperatures and pressures and the phase transitions between them.

Acids and Bases

• Acids are substances that release hydrogen ions (H+) in solution, while bases release hydroxide ions (OH−).
• The pH scale measures the acidity or basicity of a solution, ranging from 0 (strongly acidic) to 14 (strongly basic). Neutral solutions have a pH of 7.
• Buffers resist changes in pH by reacting with added H+ or OH− ions.
• Neutralization reactions occur between acids and bases, producing a salt and water.

Thermodynamics

• Thermodynamics is the study of energy transfer and its effect on a chemical system.
• The first law of thermodynamics states that energy can neither be created nor destroyed, only transformed.
• The second law of thermodynamics states that the entropy of an isolated system can only increase over time.
• The third law of thermodynamics states that the entropy of a perfect crystal at absolute zero is zero.
• Enthalpy (ΔH) is a measure of the heat absorbed or released by a system during a chemical reaction or process at constant pressure.

Solutions

• A solution is a homogeneous mixture composed of a solute dissolved in a solvent.
• The concentration of a solution describes the amount of solute present in a given amount of solvent or solution.
• Solutions can be described by various concentration units, including molarity, molality, percent by mass, and parts per million.
• Colligative properties are properties of solutions that depend on the concentration of solute particles, but not on their identity. Examples include vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure.