Chapter 2 and 3 QUIZ

What are atoms, according to Dalton's Model?

Indivisible particles that make up all matter.

What does J.J. Thomson's model of the atom propose?

Atoms have negatively charged electrons scattered in a positively charged area, often referred to as the 'plum pudding' model.

What did Ernest Rutherford's model introduce about the atom?

It proposes that there is a small positively charged nucleus at the center of the atom.

Describe the Bohr model of the atom.

It has a positive nucleus with negative electrons surrounding it, and the attraction between these particles prevents electrons from leaving.

What happens to an electron when an atom absorbs energy?

The electron moves to a higher energy level (excited state), which is unstable, and it eventually falls back to the ground state, emitting energy in the form of EM radiation.

What is quantization in the context of atomic energy?

The concept that energy levels of an atom are limited to certain fixed values, rather than being continuous.

What defines isotopes?

Atoms that have the same number of protons but different numbers of neutrons.

What is the purpose of a mass spectrometer?

To measure the masses of different isotopes and their relative abundances.

Explain the trend in ionization energy across a period.

Ionization energy increases across a period due to increasing nuclear charge, which enhances the attraction between the nucleus and outer electrons.

What is the significance of effective nuclear charge?

The actual charge experienced by valence electrons, accounting for shielding effects from inner electrons.

How do atomic radii change across a period and down a group?

Atomic radius decreases across a period and increases down a group.

What is the relationship between electronegativity and atomic structure?

Electronegativity increases across a period and decreases down a group; higher nuclear charge leads to stronger attraction for bonding electrons.

What is unique about the coordination number in complexes?

The number of dative covalent bonds formed between the ligand and the central metal ion.

What does Heisenberg's Uncertainty Principle state?

It is impossible to know both the exact position and momentum of an electron simultaneously.

What is the Aufbau Principle?

Electrons are filled into the lowest energy orbitals first before moving to higher energy levels.

What is the role of the ligand in transition metal complexes?

Ligands donate a lone pair of electrons to form dative covalent bonds with the central metal ion.

Describe how transition metal complexes absorb light.

They absorb visible light due to partially filled d orbitals, which are split into two energy sublevels by the electric field of the ligands.

What is a resonance structure?

A set of two or more Lewis structures that represent the same molecule, indicating the distribution of electrons.

What does electronegativity indicate?

The tendency of an atom to attract electrons towards itself in a chemical bond.

Explain hybridization in chemistry.

The process of combining atomic orbitals to create new hybrid orbitals for bonding.

What are transition metals?

Elements that have partially filled d orbitals and exhibit variable oxidation states.

What is a ligand in coordination chemistry?

A molecule or ion that donates a pair of electrons to a central metal ion in a complex.

What are the key features of metals?

Metals are typically malleable, ductile, conductive, and have a lustrous appearance.

What is the significance of the periodic table's organization?

It reflects the periodic trends in element properties such as atomic size, electronegativity, and ionization energy.

What is the Pauli Exclusion Principle?

No two electrons in an atom can have the same set of quantum numbers, meaning each electron has a unique state.

Explain the difference between endothermic and exothermic reactions.

Endothermic reactions absorb heat, while exothermic reactions release heat.

What is a titration?

A technique used to determine the concentration of a solute in a solution by reacting it with a solution of known concentration.

Define a redox reaction.

A reaction involving the transfer of electrons between two species, leading to changes in oxidation states.

What is a quantum number?

A number that describes the properties of atomic orbitals and the electrons in those orbitals.

What is the concept of oxidation states?

The charge of an atom in a compound, indicating its ability to donate or accept electrons during a chemical reaction.

What characterizes a polar molecule?

A molecule with an uneven distribution of charge, resulting in partial positive and negative poles.

What is enthalpy?

The total heat content of a system, used in thermodynamics to describe energy changes.

Define a ligand in coordination chemistry.

A molecule or ion that donates a pair of electrons to a central metal ion to form a coordination complex.

What is an ionic compound?

A compound formed from the electrostatic attraction between positively and negatively charged ions.

What are the five steps of a mass spectrometer?

1. Ionization - atoms are ionized to form charged particles. 2. Acceleration - ions are accelerated by an electric field. 3. Deflection - ions are deflected in a magnetic field based on their mass-to-charge ratio. 4. Detection - ions are detected, usually by a mass detector. 5. Data analysis - results are analyzed to determine the masses and abundances of isotopes.

What is oxidation?

Oxidation is the loss of electrons by an atom or ion during a chemical reaction.