Pierre curie was the one who discovered radium
Hello,
Average speed is total distance divided by total time. From the problem, our total distance is given as 500 kilometers and given time is 5 hours. Therefore, the average speed is:

Therefore, the average speed is 100 km/h. Please let me know if you have any questions!
The valence electrons are the electrons in the outermost electron shell of an atom.
Explanation:
The number of electrons in an atom's outermost valence shell governs its bondingbehaviour.
That is why elements whose atoms have the same number of valence electrons are grouped together in the Periodic Table.
Generally, elements in Groups 1, 2, and 13 to 17 tend to react to form a closed shell, corresponding to the electron configuration <span><span>s2</span><span>p6</span></span>.
This tendency is called the octet rule, because the bonded atoms have eight valence electrons.
Explanation:
a) 
where
is the distance of the mass
from the axis of rotation. When the axis of rotation is placed at the end of the rod, the moment of inertia is due only to one mass. Therefore,

b) When the axis of rotation is placed on the center of the rod, the moment is due to both masses and the radius r is 1.5 m. Therefore,

The highest point of a wave is called the crest. Among the choices, the correct answer is C. The height of the wave can be determined using the crest and the trough. The trough is the lowest point of a wave. The wavelength is the distance between two crests of a wave.