Introduction to Science and Its Divisions

Science

• Science is the study of accumulated and accepted knowledge, systematized and formulated as a basis for discovering general truths.
• Derived from the Latin word "scire," meaning to know or knowledge.
• Chemistry plays a crucial role in many aspects of public concern, offering advantages like improved healthcare, resource conservation, environmental protection, and advancements in food, clothing, and shelter.
• Disadvantages include some chemicals potentially harming health

Division of Science

• Social Sciences: Study of human behavior. Includes Anthropology (study of man and culture), Economics (allocation of resources), and Sociology (origin and structure of society).
• Natural Sciences: Study of natural objects and phenomena. Subdivided into Physical and Biological Sciences.

Physical Sciences

• Astronomy: Study of celestial bodies
• Chemistry: Study of the structure, properties, and composition of substances, and their transformations.
• Geology: Study of Earth.
• Mathematics: Study of quantities.

Biological Sciences

• Microbiology: Study of microorganisms.
• Botany: Study of plants.
• Zoology: Study of animals.

Chemistry

• Is the study of matter, its properties, and changes.
• Aims to distinguish different kinds of matter, separate substances, influence changes in matter, and determine the energy involved.

Analytical Chemistry

• Qualitative Analysis: Identification of the elements or compounds present in a sample.
• Quantitative Analysis: Determination of the ratios and percentages of elements or compounds in a sample.

Matter

• Anything that occupies space and has mass
• Pure Substances: Fixed composition. Cannot be further purified. Classified as:
  • Elements: Cannot be subdivided by chemical or physical means.
  • Compounds: Elements united in fixed ratios.
• Mixtures: Combination of two or more pure substances. Classified as: Homogeneous: Uniform composition throughout. Heterogeneous: Non-uniform composition.

Intensive and Extensive Properties

• Intensive Property: Independent of the quantity of the substance (e.g., density, specific gravity).
• Extensive Property: Depends on the quantity of the substance (e.g., mass, volume).

Classification of Matter

• Elements: Substances composed of only one type of atom (e.g., carbon, hydrogen).
• Compounds: Substances composed of two or more different types of atoms chemically bonded in a fixed ratio (e.g., water).
• Mixtures: Combinations of elements or compounds not chemically bonded and not in a fixed ratio. Classified as homogenous or heterogeneous, meaning their properties are uniform or vary from place to place

Atoms, Molecules, and Atomic Structure

• Atoms: The fundamental units of elements comprised of a nucleus and electrons orbiting the nucleus. The nucleus contains protons and neutrons.
• Molecules: Tightly-bound combinations of two or more atoms that act as a single unit.
• Atomic Models: Models illustrating the structure of atoms, such as the plum pudding model and the Bohr model (planetary model). Also, including the Wave Mechanical Model based on quantum mechanics.
• Atomic number: Number of protons
• Mass Number: Sum of protons and neutrons
• Isotopes: Atoms of the same element with different numbers of neutrons, thus different masses.

Electron Configuration

• Electronic configuration: Arrangement of electrons in energy levels, orbitals, and subshells surrounding the atom's nucleus..

Periodic Table

• Elements are arranged in order of increasing atomic number.
• Elements with similar chemical properties are grouped together in vertical columns (groups or families).
• Horizontal rows are called periods. A families are representative elements. B families are called transition elements. 10-member sequences related to stepwise addition of electrons to d orbitals.
• Elements are also categorized as metals, nonmetals, and metalloids based on their properties.

Chemical Bonding

• Ionic bonding: Transfer of electrons between atoms creating ions that attract. The strong attraction between oppositely charged ions forms a crystal.
  • An ion is an atom that has lost or gained electrons; when it loses electrons it becomes a cation; when it gains electrons it becomes an anion.
• Covalent bonding: Sharing of electrons between atoms. Polar covalent bonds share electrons unequally, non-polar share them equally.
• Metallic bonding: Sharing of electrons by many atoms in a sea of delocalized electrons, allowing metals to conduct heat and electricity.

Intermolecular Forces

• London Dispersion Forces: Weak, temporary forces of attraction occurring between any two molecules.
• Dipole-Dipole Forces: Permanent forces of attraction between polar molecules, caused by the attraction between partial positive and negative charges.
• Hydrogen Bonds: Strong dipole-dipole interactions that result from attraction between hydrogen of one molecule and a highly electronegative atom (N, O, or F) in another molecule.

Chemical Reactions

• Reactants: Substances undergoing a chemical change.
• Products: Substances produced by a chemical change.
• Chemical equations: Representation of chemical reactions using chemical symbols and formulas.
• Balancing Chemical Equations: Ensuring the law of conservation of mass holds true by adjusting coefficients in front of formulas.
• Typical Types of Chemical Reactions: - Combination/Composition Reactions - Decomposition Reactions - Single Replacement Reactions - Double Replacement Reactions

Oxidation-reduction (Redox) Reactions

• Oxidation: Loss of electrons/increase in oxidation number.
• Reduction: Gain of electrons/decrease in oxidation number.
• Oxidation numbers: Arbitrary values assigned to elements in compounds to indicate their oxidation state during a reaction..

Explore the vast field of science, covering its definition, divisions, and the critical roles of chemistry and other physical sciences. Delve into the social sciences, such as anthropology, economics, and sociology, as well as the basic principles of natural sciences. This quiz will test your understanding of these fundamental concepts.