The allowable concentration level of vinyl chloride, C2H3Cl in a chemical plant is 0.00000205g/dm^3. How many molecules of vinyl chloride in each dm^3 does this represent?

Zoe is investigating the composition of substance a, an unknown substance. using chemical processes, she analyzes substance a and determines it is composed of sodium, oxygen, and hydrogen atoms in a ratio of 1 : 1 : 1. what is substance a? a. a compound b. an element c. a heterogeneous mixture d. a homogeneous mixture

Joan writes four numbers on the board in standard form, and then she writes their scientific notation

In in , is to a 28.4-g (1-oz)−23.0 °c to −1.0 °c?