ScienceHow to use these pages
Each topic takes about ten minutes to read. Read the explanation, note the key terms, try the activity and then answer the quick questions without looking. Tap "Mark this topic as learnt" when you can answer them all; a tick then appears beside the topic in these lists, in your browser.
The class range is a typical guide. Your board or school may teach a topic a year earlier or later, so look for the topic by name. For examinations, read the same chapter in your prescribed textbook. How to study science has a simple plan.
What changes in classes 9 and 10
High school science becomes exact. Ideas now come with units, formulas and equations: force in newtons, work in joules, current in amperes, reactions written as balanced equations. It is not enough to know that a harder push speeds a thing up more; you are expected to calculate how much. The topics here are the ones later chapters and board examinations lean on most.
A good order to read in
In physics, read Newton's laws of motion first, then gravitation, then work, energy and power; each uses the one before. Electric current and Ohm's law can be read on its own. In chemistry, start with atoms and molecules, go on to the periodic table, and finish with chemical reactions and equations, which needs both.
How to study at this level
- Write every formula with the meaning and unit of each letter. A formula without units is half learnt.
- Work numerical problems with pen and paper, in steps: what is given, what is asked, the formula, the substitution, the answer with its unit.
- Balance a few chemical equations every day until counting atoms on both sides becomes a habit.
- After reading a topic, close the page and write down its main points from memory. What you cannot recall is what you need to read again.
- Use these pages for understanding, and your own textbook for the exact wording and the exercises your board expects.