South 고등학교 1학년 Integrated Science 1
Chapters: 3
1. Foundations of science
Describing nature in time and space · Base quantities and units · Measurement and estimation · Measuring and analysing change
- Measurement and Units: How We Measure Anything – To measure something is to compare it with a fixed amount called a unit. Every measurement has a number and a unit. Scientists everywhere use the SI system, with seven base units such as the metre, kilogram and second. Prefixes like kilo (×1000), centi (÷100) and milli (÷1000) make units bigger or smaller. A good measurement starts at zero, is read with the eye straight above the mark, and is only as accurate as the smallest division (least count). Rounded values hide a small range, given by upper and lower bounds.
- Units and Measurement (Class 11) – To measure means to compare a quantity with a fixed, agreed amount called a unit. Result = number × unit. The world now uses the SI system with 7 base units: metre, kilogram, second, ampere, kelvin, mole and candela. Every other unit (like newton or joule) is a derived unit made by multiplying or dividing base units. Prefixes like kilo (10³) and milli (10⁻³) make very big or very small numbers easy.
- Data Analysis – Data analysis means turning raw data into answers. It follows a cycle: ask a question, collect data, clean it (remove errors, repeats and blanks), organise and transform it, analyse it with summaries such as mean, median, range and patterns, show it with a good chart, and draw a careful conclusion. Watch for outliers, small samples and bias, and remember that a correlation between two things does not prove that one causes the other. Data must also be stored safely and used with permission.
2. Matter and regularity
Spectra and early universe elements · Stellar origin of elements · Periodic properties of elements · Ionic and covalent bonding · Building blocks of crust and life · Conductors, semiconductors, insulators
- Cosmology: The Expanding Universe and the Big Bang – Cosmology is the study of the whole universe: its structure, history and future. Galaxies gather in groups, clusters and filaments around huge voids. Distant galaxies are moving away from us, faster the farther they are (Hubble's law, v = H₀d), because space itself is expanding. Running the expansion backwards leads to a hot, dense beginning about 13.8 billion years ago, the Big Bang. The main evidence is redshift, the cosmic microwave background and the amounts of hydrogen and helium. Most of the universe is dark matter and dark energy.
- Periodic Classification of Elements – Scientists sorted elements so that similar ones sit together. Döbereiner made triads, Newlands found that every 8th element repeats (octaves), Mendeleev arranged elements by atomic mass and left gaps for unknown ones. Moseley showed that atomic number is the real key. Modern periodic law: the properties of elements are a periodic function of their atomic numbers. The modern table has 7 periods and 18 groups. Elements with Z > 100 get temporary IUPAC names built from digit roots (nil, un, bi, tri, quad, pent, hex, sept, oct, enn) plus -ium.
- Kossel-Lewis Approach and the Ionic Bond – Atoms join so that each gets a stable outer shell of 8 electrons (an octet), like a noble gas. Kossel said atoms can give or take electrons to make ions (ionic bond). Lewis said atoms can also share pairs of electrons (covalent bond). Lewis structures show these electrons as dots and lines. Formal charge (V − L − B/2) helps pick the best Lewis structure. Ions pack into a crystal, and the energy released is linked to the lattice enthalpy.
- Silicate Minerals: How One Tiny Brick Builds Most of the Earth's Crust – Silicate minerals are minerals built from silicon and oxygen. Their basic brick is the SiO₄ tetrahedron: one silicon atom with four oxygen atoms around it. Tetrahedra can stay alone or share oxygens to form chains, sheets or a 3D framework. The way they link decides the mineral's shape, cleavage and hardness. Silicates make up over 90% of the Earth's crust.
- Semiconductors and the p-n Junction Diode – A semiconductor has a small energy gap (about 1 eV), so a little heat frees some electrons. Pure silicon is intrinsic (electrons = holes). Adding a 5-valence atom makes n-type; a 3-valence atom makes p-type. Joining p and n makes a junction with a depletion layer and a barrier (about 0.7 V for Si). The diode conducts in forward bias, almost not in reverse bias, so it can change AC into one-way DC (rectifier).
3. Systems and interaction
Earth system in the solar system · Plate tectonics and energy · Gravity and motion near Earth · Inertia, momentum, collisions · Chemical reactions in cells · Information flow in cells
- Earth as a System: Spheres and Energy – Earth is like one big machine with five parts: rock (geosphere), water (hydrosphere), ice (cryosphere), air (atmosphere) and life (biosphere). The Sun powers it. Sunlight comes as many kinds of rays (the electromagnetic spectrum). The Sun heats Earth unevenly, and that makes winds, breezes and ocean currents. Water, carbon, nitrogen and oxygen move round and round between the spheres in cycles. Humans now change these cycles, so we must use Earth carefully.
- Distribution of Oceans and Continents: Drift, Spreading and Plates – In 1912 Alfred Wegener said all continents were once one landmass, Pangaea, surrounded by one ocean, Panthalassa, and that they drifted apart. Matching coastlines, rocks, fossils, glacier deposits and placer gold supported him, but he could not explain the force. Mapping the ocean floor showed ridges, plains and trenches; Harry Hess then proposed sea-floor spreading: new crust forms at mid-ocean ridges and old crust sinks at trenches. This led to plate tectonics: the lithosphere is broken into rigid plates that move on the soft asthenosphere and meet at divergent, convergent and transform boundaries. The Indian plate broke away from the south, moved north, and collided with Asia to raise the Himalayas.
- Gravity – Gravity is the pull between all masses. Earth pulls every object towards its centre. A freely falling object speeds up by about 9.8 m/s every second (g), and this does not depend on its mass. Weight is the pull on your mass, W = m × g, so it changes from world to world while mass does not. A ball thrown sideways fast enough keeps missing the Earth and goes into orbit (about 7.9 km/s); at about 11.2 km/s it escapes.
- Force and Laws of Motion – A force is a push or a pull. Balanced forces (net force zero) do not change motion; an unbalanced force changes speed or direction. Friction opposes sliding. First law: a body keeps its state of rest or uniform motion unless an unbalanced force acts (inertia; heavier bodies have more inertia). Momentum p = mv. Second law: F = ma (rate of change of momentum), 1 N = 1 kg m/s². Third law: forces come in equal and opposite pairs acting on two different bodies. For a system with no outside force, internal forces cancel and total momentum is conserved.
- Metabolism: How Cells Build, Break and Use Energy – Metabolism is the full set of chemical reactions inside a living thing. Breaking big molecules into small ones is catabolism; it gives out energy. Building big molecules from small ones is anabolism; it uses energy. ATP carries the energy between the two, like a rechargeable battery. Each reaction is sped up by its own enzyme, and the reactions link into chains called metabolic pathways.