Explore curated topics aligned to Class 9–12 curriculum. Filter by class and subject, or search by name.
2962 topics
Acid strength of hydrogen halides in water increases HF < HCl < HBr < HI. HF is weak because the H–F bond is very strong and ionisation is incomplete — not…
A catalyst added to a reaction mixture speeds up both the forward and the reverse reaction to the same degree. Thus, the catalyst has no effect on the…
A coordinate covalent bond is a type of covalent bond where the shared electron pair comes from a single atom (called the donor). Simple…
A tsunami is a series of large ocean waves from sudden water displacement; near coasts speed falls while height can rise sharply.
A histogram uses bars. A frequency polygon joins the midpoints of the class tops (or the midpoints at class marks) with straight lines, often closing to the…
A three-pin plug connects live, neutral, and earth conductors with IEC colours brown, blue, and green/yellow respectively.
Quantitative Research is a research method that focuses on collecting and analyzing numerical data to identify patterns, test theories, and make…
Under extreme physical conditions, matter can enter unusual states in which ordinary classical-gas descriptions no longer apply, including degenerate matter,…
CO: colourless, from incomplete combustion in poor ventilation (heater slogan: service and vents, emergency help if headache/confusion — medical services, not…
An identity is true for all allowed angles, not just one triangle you measured. Class 9 needs sin^2 theta + cos^2 theta = 1, tan theta = sin theta / cos theta,…
A vibrating tuning fork is held above the open end of a glass tube whose lower end is closed by water. Lowering the water changes the air-column length. At…
Do not subtract upper limit from lower limit blindly if the classes are 1-10, 11-20: 10 - 1 = 9 would be the wrong width. Subtract consecutive lower limits: 11…
Permanent Magnet: A magnet that retains its magnetism for a long period of time without the need for an external power source. It is made from hard…
Science asks why: why does a current make a magnetic field? After we understand it, technology is the useful object or method: the electromagnet, the electric…
Role of Chemical Kinetics in the Food Industry: The application of the principles of reaction rates and collision theory to understand, control, and…
From two sets you build new sets with everyday words. Union A union B is the set of elements in A or B or both. Intersection A intersect B is the set of…
A ligand substitution reaction (also called a ligand exchange reaction) is a reaction in which one ligand in a complex is substituted by another ligand.…
Prions: Prions are infectious protein particles, smaller than viruses, that contain no nucleic acids (neither DNA nor RNA). Viroids: Viroids are…
Relative Strength of Magnetic Field refers to how strong or weak the magnetic field is at a particular point compared to another point. It is determined by…
Tr+1 = nCr an-r br . To find a particular power, set the exponent of x (or a) equal to the wanted power and solve for r (r must be an integer 0 to n).…
For |x|<1, (1+x)n = 1 + n x + n(n-1)/2! x2 + n(n-1)n-23! x^3 + ... even if n is not a positive integer. You usually keep the first few terms…
Salts: Salts are ionic compounds formed through the electrostatic attraction between oppositely charged ions. These ions originate from acids…
Conventional websites are static since they are only made with HTML and CSS. Every time a user visits the website, the same content is displayed. This…
Time of summit is the time to reach maximum height: ts = vi sin θg.
