Concept explainers
(a)
Interpretation:
The number of significant digits present in each of the numbers has to be given.
Concept Introduction:
Significant digits:
In a number, the digits which contribute to the precision of the number are said to be significant digits.
Rules for determination of significant digits in a number:
- All non-zero digits are significant.
- The zeros appearing between two non-zero digits are significant.
- The zeros before the non-zero numbers are not significant.
- Zeros after non-zero number without decimal are non significant.
- Zeros after non-zero number with decimal are significant.
- Zeros after the decimal point are significant.
- Any numbers with scientific notation are significant.
(b)
Interpretation:
The given numbers has to be rounded to three significant digits.
Concept Introduction:
Rounding off a number:
- The last digit retained is left unchanged if the following digit is less than five.
- The last digit retained is increased by one if the following digit is greater than five.
- If the last digit retained is followed by a single digit of five or by a five followed by zeros, then the last digit is increased by one if it is odd number and remains as same if it is even number.
(c)
Interpretation:
The calculations have to be done and the result has to be rounded to the proper number of significant digits.
Concept Introduction:
The sum of the significant digits has to be given in the lowest decimal present in the values.
The significant digit in multiplication and division has to be given as the quantity with the fewest significant figures.
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Chemistry: The Molecular Science
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