A mystery element "X” has two stable isotopes X-50 which occurs 40% of the time and X-60 which occurs 60% of the time. What is the average mass of element "X"?

A-50 amu
B-54 amu
C-56 amu
D-60 amu

Two atoms interact with each other as shown by the equation. complete the equation by filling in the missing parts. 1 2 3 4 5 h he li

Describe the difference between a. a hypothesis and a theory and b. an observation and an experiment.

Consider the reaction of a(g) + b(g) + c(g) => d(g) for which the following data were obtained: experiment initial [a], mol/l initial [b], mol/l initial [c], mol/l initial rate, mol/l.s 1 0.0500 0.0500 0.0100 6.25 x 10^-3 2 0.100 0.0500 0.0100 2.50 x 10^-2 3 0.100 0.100 0.0100 1.00 x 10^-1 4 0.0500 0.0500 0.0200 6.25 x 10^-3 what is the rate law for the reaction?