Which sample of argon contains a total of 3.01 x 10^23 molecules at STP?
A)40.0g B)22.4L C)20.0g D)11.2L

In an energy pyramid, which level has the most available energy?

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

Which position represents spring in the southern hemisphere? a) b) c) d)