Question

How many significant figures are in each of the following quantities a.45.26ft b.0.109in c.0.00025kg d.2.3659Ã10rest to the power -8cm e.,52.0cm3 f.0.0020kg g.8.50Ã10rest to the power 4 mm h.300.0

Answer 1

Answer :

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

Rules for significant figures:

• Digits from 1 to 9 are always significant and have infinite number of significant figures.
• All non-zero numbers are always significant. For example: 654, 6.54 and 65.4 all have three significant figures.
• All zero’s between integers are always significant. For example: 5005, 5.005 and 50.05 all have four significant figures.
• All zero’s preceding the first integers are never significant. For example: 0.0078 has two significant figures.
• All zero’s after the decimal point are always significant. For example: 4.500, 45.00 and 450.0 all have four significant figures.
• All zeroes used solely for spacing the decimal point are not significant. For example : 8000 has one significant figure.

(a) 45.26 ft

In this quantity, there are 4 significant figures which are 4, 5, 2 and 6.

(b) 0.109 in

In this quantity, there are 3 significant figures which are 1, 0 and 9.

(c) 0.00025 kg

In this quantity, there are 2 significant figures which are 2 and 5.

(d) $2.3659\times 10^{-8}cm$

In this quantity, there are 5 significant figures which are 2, 3, 6, 5 and 9.

(e) $52.0cm^3$

In this quantity, there are 3 significant figures which are 5, 2 and 0.

(f) 0.0020 kg

In this quantity, there are 2 significant figures which are 2 and 0.

(g) $8.50\times 10^{4}mm$

In this quantity, there are 3 significant figures which are 8, 5 and 0.

(h) 300.0

In this quantity, there are 4 significant figures which are 3 and all zero.

Answer 2

Answer:

(a) 45.26 ft

In this quantity, there are 4 significant figures which are 4, 5, 2 and 6.

(b) 0.109 in

In this quantity, there are 3 significant figures which are 1, 0 and 9.

(c) 0.00025 kg

In this quantity, there are 2 significant figures which are 2 and 5.

(d) 2.3659\times 10^{-8}cm2.3659×10

−8

cm

In this quantity, there are 5 significant figures which are 2, 3, 6, 5 and 9.

(e) 52.0cm^352.0cm

3

In this quantity, there are 3 significant figures which are 5, 2 and 0.

(f) 0.0020 kg

In this quantity, there are 2 significant figures which are 2 and 0.

(g) 8.50\times 10^{4}mm8.50×10

4

mm

In this quantity, there are 3 significant figures which are 8, 5 and 0.

(h) 300.0

In this quantity, there are 4 significant figures which are 3 and all zero.