Explain Scientific Notation and highlight the Convention for Indicating the Units?
- Scientific Notation. Expression of Numbers in standard decimal form employing powers of ten is called scientific notation. The internationally accepted practice is that there should be only one non-zero digit left of decimal. Thus, the number 134.7 should be written as 1.347 x 102 and 0.0023 should be expressed as 2.3×10-3
- Conventions for Indicating Units. Use of SI units requires special care, more particularly in writing prefixes. Following points should be kept in mind while using units:
- Full name of the unit does not begin with a capital letter even if named after a scientist e.g. Newton.
- The symbol of unit named after a scientist has initial capital letter such as N for newton.
- The prefix should be written before the Unit without any space, such as I x 10-3m is written as 1 mm. Standard prefixes are given in table below
- A combination of base units is written each with one space apart. For example, newton metre is written as N m.
- Compound prefixes are not allowed. For example, lppF may be written as 1pF.
- A number such as 5.0 x i04 cm may be expressed in scientific notation as 5.0 x102
When a multiple of a base unit is raised to a power, the power applies to the Whole multiple and not the base unit alone. Thus, 1 km2 1 (km)2 = I x 10 m2.
(viii) Measurement in practical work should be recorded immediately in the most convenient unit, e.g., micrometer screw gauge measurement in mm, and the mass of calorimeter in grams (g). But before calculation for the result, all measurements must be converted to the appropriate SI base units