#### Answer

(a) 3
(b) 4
(c) 3
(d) 1
(e) 5

#### Work Step by Step

(a) In 0.136 m, all nonzero digits are significant. Therefore, there are three significant figures in this number.
(b) In 0.0001050 g, there are four significant figures. All nonzero digits are significant as well as the trailing zero and the zero between the nonzero digits.
(c) In 2.70 x 10$^3$ nm, there are three significant figures. Because the number is written with scientific notation, figuring out the significant figures is simple. The 2 and 7 are significant as well as the trailing zero.
(d) In 6 x 10$^{-4}$ L, there is one significant figure. Because the number is written with scientific notation, figuring out the significant figures is simple. The 6 is the only significant figure.
(e) In 56003, there are five significant figures. The three nonzero digits are significant as well as the two zeros between the nonzero digits.