Question

Which of the following statement is wrong concerning the significant digits? A. Three significant digits in 0.00405 B. Four significant digits in 0.05000 C. Four significant digits in 2.1870 x 102 D. Three significant digits in 1.03 E. Five significant digits in 53.410

Answer 1

A)

0.00405 --> 4.05*10^-3 will be the scientific notation, it contains only 3 digits, i.e. 3 significan figures, so it is TRUE

B)

0.05000; note that those 3 extra zeros mean precision! so we can't simply ignore them, so

5.000*10^-2; total number of digits = 4, so this is also TRUE

C)

note that in scientific notation, we only care about the "base" number i.e. the 10^2 is only informative

so

2.1870 --> 5 digits, therefore 5 significant figures, this is FALSE

d)

1.03 --> has 3 digis, so 3 sig. fig , this is TRUE

e)

53.410 --> last zero counts! since it is significative given it states precision

so, 5 digits --> 5 sig. fig, TRUE

therefore

only C) is wrong