Answer: To isolate the unknown substances, of which only tiny amounts were present, the Curies were the first to use a new method of chemical analysis. They employed various standard (but sometimes demanding) chemical procedures to separate the different substances in pitchblende.
Explanation:
Answer:
T = 99.51 hour
Explanation:
Mass of Uranus, 
The moon Umbriel orbits Uranus at a distance of 
We need to find Umbriel's orbital period. Let it is T. Using Kepler's third law of motion to find it.

As 1 hour = 3600 s
358244.51 s = 99.51 hour
Hence, Umbriel's orbital period is 99.51 hour.
Answer: the average position of all the parts of the system, weighted according to their masses.
Explanation: