#### Answer

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

#### Work Step by Step

(a) In 3.1416 degrees, there are five significant figures. All nonzero digits are significant.
(b) In 0.00314 K, there are three significant figures. All nonzero digits are significant. The leading zeros are not significant.
(c) In 1.0079 s, there are five significant figures. All nonzero digits are significant as well as the two zeros between the nonzero digits.
(d) In 6.022 x 10$^23$ particles, there are four significant figures. Because the number is written in scientific notation, it is simple to figure out the number of significant figures. All digits in 6.022 are significant.