Correct Answer: A

Rationale: A femtometer is equivalent to 10^-15 meters. The prefix 'femto-' signifies a factor of one quadrillionth (10^-15), making choice A the correct answer. Choice B (10^-9 meters) represents a nanometer, not a femtometer. Choice C (10^-12 meters) corresponds to a picometer, not a femtometer. Choice D (10^-18 meters) is even smaller than a femtometer and refers to an attometer, not a femtometer.

Correct Answer: B

Rationale: To convert milliliters to liters, you need to divide by 1000 since 1 liter is equal to 1000 milliliters. Therefore, 500 milliliters divided by 1000 equals 0.5 liters. Choice A (0.05 liters) is incorrect because it represents 50 milliliters, not 500 milliliters. Choice C (5 liters) and Choice D (50 liters) are both incorrect as they are higher values and do not accurately represent the conversion of 500 milliliters to liters.

Correct Answer: A

Rationale: To convert 0.875 to a fraction, express it as 875\10000. Simplifying this fraction by dividing both the numerator and denominator by 125 results in 7\80.

Correct Answer: B

Rationale: To convert liters to milliliters, you need to multiply by 1000, not 10000. Therefore, 0.2 liters equals 200 ml (0.2 x 1000 = 200 ml). Choice A, 20 ml, is incorrect because it's the result of multiplying by 10 instead of 1000. Choice C, 2 ml, is incorrect as it's the result of ignoring the decimal point. Choice D, 2000 ml, is incorrect because it's the result of multiplying by 10000.

Correct Answer: A

Rationale: To convert milliliters to liters, you need to divide by 1000 since there are 1000 milliliters in a liter. Therefore, the correct conversion factor is 0.001 liters (1 liter = 1000 milliliters). Choice B (0.01 liters) is incorrect as it suggests dividing by 100, which is not the correct conversion. Choice C (1 liter) is incorrect because it is the equivalent value in liters, not the conversion factor. Choice D (10 liters) is incorrect as it is not the correct conversion of milliliters to liters.