Question

uncertainty in measurement quiz
cp chemistry a 0 / module 1: chemistry basics

1. which of the following are exact numbers? select all that apply.

the liquid has a volume of 10.41 ml
the paper has a length of 5.2 cm.
there are 30 students in the class.
there are 100 cm in 1 m.

Explanation:

1. For "The liquid has a volume of 10.41 mL" and "The paper has a length of 5.2 cm", these are measured values with uncertainty (from the measuring instrument), so they are not exact.
2. "There are 30 students in the class" is a counted number (you can precisely count the students), so it's exact.
3. "There are 100 cm in 1 m" is a defined conversion (by definition, 1 meter is exactly 100 centimeters), so it's exact.

Answer:

C. There are 30 students in the class, D. There are 100 cm in 1 m