Introduction to Chemistry Quiz

Definition: The study of matter, its properties, composition, and reactions.
Branches:
- Organic Chemistry: Study of carbon-containing compounds.
- Inorganic Chemistry: Study of inorganic compounds.
- Physical Chemistry: Study of the physical properties of molecules.
- Analytical Chemistry: Techniques for analyzing substances.
- Biochemistry: Chemistry of biological processes.

Definition: Anything that has mass and occupies space.
States of Matter:
- Solid: Defined shape and volume.
- Liquid: Defined volume, takes the shape of the container.
- Gas: No defined shape or volume, expands to fill the container.
Changes in State: Melting, freezing, condensation, evaporation, sublimation.

Atoms: Basic units of matter, consisting of:
- Protons: Positively charged, found in the nucleus.
- Neutrons: Neutral, found in the nucleus.
- Electrons: Negatively charged, orbit the nucleus.
Atomic Number: Number of protons in an atom.
Mass Number: Total number of protons and neutrons.

Organization: Elements arranged by increasing atomic number.
Groups: Columns (elements with similar properties).
Periods: Rows (elements with increasing atomic number).
Key Groups:
- Alkali Metals (Group 1)
- Alkaline Earth Metals (Group 2)
- Transition Metals (Groups 3-12)
- Halogens (Group 17)
- Noble Gases (Group 18)

Ionic Bonds: Formed through the transfer of electrons from one atom to another (usually between metals and nonmetals).
Covalent Bonds: Formed by sharing electrons between atoms (usually between nonmetals).
Metallic Bonds: Attraction between metal atoms and the surrounding sea of electrons.

Definition: Process in which substances (reactants) are transformed into new substances (products).
Types of Reactions:
- Synthesis: Combining elements/compounds to form a new compound.
- Decomposition: Breaking down a compound into simpler substances.
- Single Replacement: An element replaces another in a compound.
- Double Replacement: Exchange of ions between two compounds.
- Combustion: Reaction with oxygen to produce energy (usually involving hydrocarbons).

Definition: The calculation of reactants and products in chemical reactions.
Mole Concept:
- 1 mole = 6.022 x 10²³ particles (Avogadro's number).
- Molar mass: Mass of one mole of a substance (g/mol).

Acids: Substances that donate protons (H⁺) in a solution.
- Characteristics: Sour taste, turn blue litmus paper red.
Bases: Substances that accept protons or donate hydroxide ions (OH⁻).
- Characteristics: Bitter taste, slippery feel, turn red litmus paper blue.
pH scale: Measures acidity (0-14); 7 is neutral, <7 is acidic, >7 is basic.

Definition: Study of energy changes in chemical reactions.
Key Concepts:
- Enthalpy (ΔH): Heat content; changes in enthalpy during a reaction indicate if it is exothermic (releases heat) or endothermic (absorbs heat).
- Entropy (ΔS): Measure of disorder; reactions tend to favor increased entropy.
- Gibbs Free Energy (ΔG): Indicates spontaneity of a reaction (ΔG < 0 is spontaneous).

Chemistry is foundational to understanding the material world and provides insight into the composition, structure, and changes of matter.

Defined as anything that has mass and occupies space.
States of Matter:
- Solid: Fixed shape and volume.
- Liquid: Fixed volume, adapts to the container's shape.
- Gas: Lacks fixed shape and volume; expands to fill the container.
Changes in State: Includes melting, freezing, condensation, evaporation, sublimation.

Atoms are the fundamental units of matter.
Composed of:
- Protons: Positively charged particles located in the nucleus.
- Neutrons: Neutral particles also found in the nucleus.
- Electrons: Negatively charged, orbiting around the nucleus.
Atomic Number: Number of protons in an atom, defines the element.
Mass Number: Total of protons and neutrons in an atom.

Ionic Bonds: Formed by the transfer of electrons between atoms (common between metals and nonmetals).
Covalent Bonds: Formed through shared electrons (usually between nonmetals).
Metallic Bonds: Created by the attraction between metal atoms and a sea of delocalized electrons.

Involves calculations related to the quantities of reactants and products in chemical reactions.
Mole Concept:
- One mole equals 6.022 x 10²³ representative particles (Avogadro's number).
- Molar Mass: The mass of one mole of a substance, measured in grams per mole (g/mol).

Acids: Substances that release protons (H⁺) in solution; exhibit sour taste and turn blue litmus paper red.
Bases: Substances that accept protons or provide hydroxide ions (OH⁻); showcase bitter taste, slippery feel, and turn red litmus paper blue.
pH Scale: Ranges from 0 to 14; values below 7 indicate acidity, 7 is neutral, and above 7 indicates basicity.

Study of energy changes during chemical reactions.
Key Concepts:
- Enthalpy (ΔH): Heat content; indicates if a reaction is exothermic (heat released) or endothermic (heat absorbed).
- Entropy (ΔS): Measures disorder; reactions generally favor increased entropy.
- Gibbs Free Energy (ΔG): Determines spontaneity; a negative ΔG indicates a spontaneous reaction.