South 고등학교 1학년 Integrated Science 2
Chapters: 3
1. Change and diversity
Earth's changing environment through time · Variation and natural selection · Redox reactions in nature and history · Acids, bases and neutralisation · Energy absorbed and released
- Evolution: How New Kinds of Living Things Arise – Variations arise during reproduction. Nature selects those that help survival, so over many generations populations change: this is evolution. Only inherited (DNA) changes pass on; acquired changes do not. Separated populations can become new species. Homologous organs, analogous organs and fossils help us trace who is related to whom, and complex organs evolved step by step.
- Oxidation and Reduction: Corrosion and Rancidity – Oxidation is gain of oxygen (or loss of hydrogen); reduction is loss of oxygen (or gain of hydrogen). They always happen together, so these are called redox reactions. The substance that gives oxygen is the oxidising agent; the one that takes it is the reducing agent. In daily life, oxidation causes corrosion (like rusting of iron) and rancidity (fats and oils going stale).
- Acids and Bases: Properties, Indicators and Reactions – An acid gives H⁺ ions in water and a base gives OH⁻ ions. Indicators show which one is present by a colour or smell change, and when H⁺ meets OH⁻ they make water, leaving a salt behind.
- Types of Chemical Reactions – Most reactions fit a few patterns. Combination: A + B → AB. Decomposition: AB → A + B. Displacement: A + BC → AC + B, where the more reactive A pushes out B. Double displacement: AB + CD → AD + CB, where partners swap; if an insoluble solid forms it is a precipitation reaction. Reactions that give out heat are exothermic; those that take in heat are endothermic.
2. Environment and energy
Ecosystem components and interactions · Food webs and ecological balance · Greenhouse effect and global warming · Solar energy from fusion · Generators and electrical energy · Energy efficiency and sustainability
- Ecosystem, Food Chains and Energy Flow – An ecosystem is all the living things in a place plus the non-living things around them, working together. Energy enters as sunlight, passes one way up a food chain, and only about 10% moves to each next level.
- Climate Change and the Greenhouse Effect – Climate is the average weather of a place over about 30 years. Greenhouse gases like carbon dioxide and methane trap some of the heat the Earth gives off. Humans have added a lot more of these gases by burning fossil fuels and cutting forests, so the Earth is warming. This causes melting ice, rising seas and more extreme weather. We can cut emissions (mitigation) and prepare for changes (adaptation).
- Nuclear Fusion – In nuclear fusion, light nuclei join to make a heavier nucleus and release energy. In the Sun's core, at about 15 million °C, four hydrogen nuclei join in steps (the proton–proton chain) to make one helium nucleus. The helium weighs about 0.7% less than the four hydrogens; that missing mass becomes energy by E = mc². Gravity squeezing in and fusion heat pushing out keep a star steady for billions of years.
- Force on a Current-Carrying Conductor, Motor and Induction – A wire carrying current inside a magnetic field feels a push. The push is biggest when the wire is at 90° to the field and zero when it is parallel. Fleming's left-hand rule gives its direction. A motor uses this push to spin a coil; a generator does the reverse and makes current by moving a coil or magnet.
- Energy Efficiency – Every machine changes energy from one form to another. Part of the energy becomes what we want (useful energy). The rest spreads out, mostly as heat (wasted energy). Efficiency = useful energy out ÷ total energy in × 100 %. No real machine reaches 100 %. Using efficient devices and wasting less energy saves money and cuts pollution.
3. Science and the future
Science against infectious disease · Big data in science and society · AI robots and IoT · Ethics in science and technology
- Public Health – Public health is the work of keeping whole communities healthy: preventing disease, promoting healthy living and making sure everyone can get care. Infectious diseases spread through air, water, food, touch and insects; hygiene, clean water, sanitation and vaccination break the chain. When enough people are immune, herd immunity protects the rest. Health systems work in levels (primary, secondary, tertiary) and use surveillance data to spot outbreaks early.
- Big Data – Big data is data that is too big, too fast or too mixed to store and process on one ordinary computer with normal tools. We describe it with Volume (how much), Velocity (how fast it arrives) and Variety (how many kinds). To handle it, the work is split across many machines that run at the same time (distributed processing, for example MapReduce). Big data is often stored as simple facts or as a graph of nodes and links, and it is used for weather forecasts, maps, health, shopping and training AI. It also raises questions about privacy and fairness.
- Artificial Intelligence: How Machines Learn to Think – Artificial intelligence (AI) is the skill of a computer system to do tasks that normally need human thinking: seeing, understanding speech, deciding and learning. An AI system is an agent that senses, thinks and acts. Old AI followed rules written by people. Modern AI mostly uses machine learning: it finds its own rule from many labelled examples (data). Neural networks are layers of simple units whose link strengths (weights) change during training. AI is used in maps, translation, health, farming and games. It can be wrong or unfair when its data is one-sided (bias), so people must check it, protect privacy and stay responsible.
- Ethics in Science and Technology – Science and technology give great power, so we also ask "should we?" and not only "can we?". Science ethics means weighing benefit against risk, keeping people, animals and nature safe, being honest with data, taking responsibility for how results are used, and letting citizens share in big decisions about science.