SSC General Science Notes: Physics, Chemistry, Biology and Environment
General Science is one of the easiest ways to collect marks in the General Awareness section of SSC exams. The syllabus is based on school-level science, so if you have studied from Class 6 to Class 10 you already know the foundation. What you need now is a quick, organised revision of the facts, units, laws and examples that SSC asks again and again. These SSC General Science notes cover Physics, Chemistry, Biology and Environment in a simple chapter-wise format.
The science notes for SSC below are suitable for SSC CGL, CHSL, MTS, GD Constable, CPO and other competitive exams. Read them once for understanding and then use the quick-fact lists for last-minute revision.
What You Get in These Science Notes
- Branch-wise notes for Physics, Chemistry, Biology and Environment
- Formulas, SI units and symbol tables for quick revision
- Vitamins, diseases and human body facts
- Easy language with examples from daily life
- Free online reading with PDF downloads for selected chapters
Physics Notes
- SI units: force: newton, pressure: pascal, work and energy: joule, power: watt, frequency: hertz, electric current: ampere, resistance: ohm, charge: coulomb.
- Equations of motion: v = u + at, s = ut + half at squared, and v squared = u squared + 2as. Force F = ma and momentum p = mv.
- Newton's laws: the first law is the law of inertia, the second gives F = ma, and the third says every action has an equal and opposite reaction.
- Work, energy and power: W = F x d, kinetic energy = half m v squared, potential energy = mgh and power = work / time.
- Gravitation: the acceleration due to gravity on the Earth is about 9.8 m/s squared and the escape velocity of the Earth is about 11.2 km/s.
- Heat: heat transfers by conduction, convection and radiation. The Celsius and Kelvin scales are related by K = C + 273.
- Light: the speed of light in vacuum is about 3 x 10 raised to 8 m/s. Mirror formula: 1/v + 1/u = 1/f. Lens formula: 1/v - 1/u = 1/f. Refractive index n = c / v. Myopia is corrected with a concave lens and hypermetropia with a convex lens.
- Sound: needs a medium to travel and moves at about 343 m/s in air. The audible range for humans is 20 Hz to 20 kHz. An echo needs a minimum distance of about 17 m.
- Electricity: Ohm's law is V = IR and electric power is P = VI. Resistances add up in series and the reciprocals add up in parallel. The SI unit of electrical energy used at home is kilowatt-hour.
Chemistry Notes
- Matter: exists as solid, liquid and gas. Physical changes are reversible, while chemical changes form new substances.
- Atom: made of protons and neutrons in the nucleus and electrons around it. Atomic number = number of protons. Isotopes have the same atomic number but different mass numbers.
- Acids, bases and salts: pH below 7 is acidic, 7 is neutral and above 7 is basic. Citric acid is in lemon, acetic acid in vinegar, lactic acid in curd, tartaric acid in tamarind and formic acid in ant stings.
- Metals and non-metals: metals are good conductors, malleable and ductile. Mercury is the only metal that is liquid at room temperature. Common alloys: brass (copper and zinc), bronze (copper and tin) and steel (iron and carbon).
- Carbon: its allotropes are diamond, graphite and fullerene. Diamond is the hardest natural substance.
- Symbols: sodium Na, potassium K, iron Fe, copper Cu, silver Ag, gold Au, lead Pb, mercury Hg, tin Sn and tungsten W.
- Common chemicals: baking soda is sodium bicarbonate (NaHCO3), common salt is sodium chloride (NaCl), quicklime is calcium oxide (CaO) and washing soda is sodium carbonate.
- Air: about 78% nitrogen, 21% oxygen and about 0.04% carbon dioxide. Noble gases are helium, neon, argon, krypton, xenon and radon.
Biology Notes
- Cell: the basic unit of life. The mitochondria is the powerhouse of the cell, the nucleus controls the cell, and chloroplasts are the sites of photosynthesis in plants.
- Photosynthesis: 6CO2 + 6H2O gives C6H12O6 + 6O2 in the presence of sunlight and chlorophyll.
- Human body: an adult has 206 bones and 32 permanent teeth. The skin is the largest organ, the liver is the largest gland, the femur is the longest bone and the stapes in the ear is the smallest bone. The heart has four chambers.
- Blood: red blood cells carry oxygen through haemoglobin (which contains iron), white blood cells fight infection and platelets help in clotting. ABO is the main blood group system.
- Hormones: insulin from the pancreas controls blood sugar, thyroxine from the thyroid controls metabolism, and a deficiency of iodine causes goitre.
- Vitamins and deficiency diseases: Vitamin A: night blindness. Vitamin B1: beriberi. Vitamin B3: pellagra. Vitamin C: scurvy. Vitamin D: rickets. Vitamin K: blood clotting problems. Iron deficiency causes anaemia.
- Diseases: bacterial diseases include tuberculosis, cholera, typhoid and tetanus. Viral diseases include polio, measles, dengue, hepatitis and influenza. Malaria is a protozoan disease spread by the female Anopheles mosquito. Ringworm is a fungal disease.
Environment and Ecology Notes
- An ecosystem is made of living (biotic) and non-living (abiotic) components. A food chain shows the flow of energy, and a food web is a network of food chains.
- Greenhouse gases include carbon dioxide, methane, nitrous oxide, CFCs and water vapour. They cause global warming and climate change.
- CFCs damage the ozone layer. The Montreal Protocol (1987) controls ozone-depleting substances, the Kyoto Protocol (1997) deals with greenhouse gas emissions and the Paris Agreement (2015) aims to limit global warming.
- Project Tiger was launched in 1973 to protect tigers. National parks, wildlife sanctuaries and biosphere reserves protect biodiversity. Ramsar sites are wetlands of international importance.
- World Environment Day is celebrated on 5 June.
High-Value Quick Facts
- Normal human body temperature is 37 degrees Celsius.
- Pure water has a pH of 7 and blood has a pH of about 7.4.
- The atomic number of carbon is 6.
- Insulin is produced by the pancreas.
- Chlorophyll is the green pigment that captures sunlight in plants.
How to Prepare General Science
- Study one branch at a time and write short notes with a table of units, laws and names.
- Use diagrams for the human body, the eye, circuits and the carbon cycle.
- Practise 20 to 25 questions for every chapter and revise the wrong answers.
- Revise your fact list every weekend so that formulas and names remain fresh.
Practice and Related Notes
Attempt the science questions from our previous year papers to see the exact style, and continue with the General Awareness and Computer Knowledge notes. You can also test yourself with the daily quiz.
Frequently Asked Questions About SSC Notes
Where can I read SSC General Science notes for free?
All General Science notes on this page are free to read online without signup. Open a branch or chapter, study the key facts and download the PDF wherever it is available for offline revision.
What level of General Science is asked in SSC exams?
SSC asks school-level science up to Class 10, covering Physics, Chemistry and Biology. The questions are mostly conceptual or fact-based, such as units, laws, chemical names, diseases and vitamins, so NCERT-level understanding is enough.
Which General Science chapters are most important?
Human body and diseases, vitamins and nutrition, basic Physics concepts (motion, light, sound, electricity), acids-bases-salts, metals and non-metals, everyday chemistry, and Environment and Ecology are among the most repeated chapters.
Are these notes enough for SSC CGL, CHSL and MTS?
They cover the General Science and Environment syllabus asked in SSC CGL, CHSL, MTS, GD and CPO. Practise questions after each chapter and solve previous year papers to confirm that you can recall the facts quickly.
How can I prepare General Science quickly?
Read each chapter once from these notes, make a list of formulas, units and facts, and then solve questions on the topic. Revise the list weekly. Diagrams and tables help to remember body systems and chemical reactions.
Is Physics difficult for non-science students?
No. SSC asks only basic concepts, units and simple formulas. Spend more time on definitions, SI units and everyday examples than on numerical problems.
Which vitamins and diseases should I remember?
Vitamin A (night blindness), B1 (beriberi), B3 (pellagra), C (scurvy), D (rickets), K (blood clotting problems). Also remember iron (anaemia) and iodine (goitre) deficiencies.
Is Environment part of the General Science section?
Environment, ecosystem, pollution, biodiversity and climate change questions are often asked along with or inside General Awareness, so they are included in these notes.
How many Science questions come in SSC exams?
The number varies by exam and shift because science questions are a part of the General Awareness section. Usually 4 to 7 questions come from science, so it is a high-return topic for the time you spend.
How much time should I give to General Science?
One hour a day for three to four weeks is enough to cover the syllabus, followed by weekly revision of the fact list and practice questions.
Do I need to read NCERT books for SSC Science?
NCERT books of Classes 6 to 10 are the base of the syllabus. These notes condense the important points so that you can revise quickly, but reading NCERT once gives extra clarity.
How do I memorise chemical formulas and symbols?
Make a table of common elements and compounds, say them aloud and use flash cards. Regular revision for five to ten minutes a day is more effective than long sessions.