Health Innovations and Environmental Impact

Health and Medicine

Sanitation systems: Significantly reduced the spread of diseases, improving public health.
Surgery with anesthesia: Allowed for more complex procedures, decreasing pain and risk for patients.
Vaccines: Provide immunity against diseases, preventing serious complications and outbreaks.
Antibiotics: Fight bacterial infections, saving lives and treating a wide range of illnesses.
Gene therapy: Offers potential for treating genetic diseases by altering faulty genes.

Energy and the Environment

Fossil fuels: Non-renewable energy sources that produce greenhouse gases, contributing to climate change.
Solar energy: Renewable and clean energy source, harnessing sunlight to generate electricity.
Nuclear energy: Highly efficient energy source, but carries risks associated with radioactive waste and potential accidents.

Materials and Technology

Polymers, ceramics, liquid crystals: Materials with unique properties used in various modern applications.
Room-temperature superconductors: Hypothetical materials with zero electrical resistance at room temperature, revolutionizing energy transmission.
Molecular computing: Emerging field aiming to use molecules for data storage and processing.

Food and Agriculture

Genetically Modified (GM) crops: Provide benefits such as increased yield, pest resistance, and enhanced nutritional value, but raise concerns about long-term effects.
Biopesticides: Use natural substances to control pests, offering an environmentally friendly alternative to synthetic pesticides.
Organic fertilizers: Derived from natural sources, enhance soil fertility and promote sustainable agricultural practices.

Chemistry

Dalton's Atomic Theory: The first scientific theory to propose that matter is composed of atoms.
Law of Multiple Proportions: When two elements combine to form more than one compound, the mass ratios of the elements in the compounds can be expressed as simple whole numbers.
Law of Conservation of Mass: In a closed system, the mass of the reactants before a chemical reaction must equal the mass of the products after the reaction.
Cathode Ray Tube Experiment (J.J. Thomson): Measurment of the charge-to-mass ratio of the electron.
Millikan's Oil Drop Experiment: Measurement of the charge of the electron, leading to determination of its mass.
Thomson's Model of the Atom: Proposed a "plum pudding" model with a positively charged sphere containing negatively charged electrons.
Rutherford's Gold Foil Experiment: Discovery of the atomic nucleus, showing that the positive charge is concentrated in a very small region within the atom.
- **Protons (p): ** Positively charged particles with a mass approximately 1840 times that of an electron.
- Neutrons (n): Neutrally charged particles with a mass similar to that of protons.
Rutherford's Model of the Atom: Proposed a model with a central, positively charged nucleus surrounded by negatively charged electrons in orbits.
Chadwick's Experiment: Discovery of neutrons, completing the understanding of the basic building blocks of the atom.
- A (Mass number): Number of protons (Z) plus number of neutrons.
- Z (Atomic number): Number of protons, which defines the element.
Isotopes: Atoms of the same element that have the same number of protons but different numbers of neutrons.
- Isotopes of Hydrogen: Protium (1H), Deuterium (2H), Tritium (3H)
Molecules: Formed by two or more atoms bonded together.
- Diatomic molecules: Contain two atoms (e.g., O2).
- Polyatomic molecules: Contain more than two atoms (e.g., H2O).
Ions: Atoms or groups of atoms with a net electric charge.
- Cations: Positively charged ions (e.g., Na+)
- Anions: Negatively charged ions (e.g., Cl-)
- Monatomic ions: Contain only one atom (e.g., Na+, Cl-)
- Polyatomic ions: Contain more than one atom (e.g., SO42−, NO3−).
Molecular formula: Represents the exact number of atoms of each element in a molecule (e.g., H2O).
Empirical formula: The simplest whole-number ratio of atoms in a compound (e.g., CH2O for glucose).
Ionic compounds: Formed by the electrostatic attraction between cations and anions.
- The formula unit is usually the same as the empirical formula.
- The sum of the charges on the cations and anions must equal zero.
Acids: Substances that produce hydrogen ions (H+) when dissolved in water (e.g., HCl).
- Oxoacids: Acids containing hydrogen, oxygen, and another element (e.g., HNO3, H2CO3, H3PO4).
Bases: Substances that produce hydroxide ions (OH-) when dissolved in water (e.g., NaOH).
Organic chemistry: The study of carbon-containing compounds.