Feet and inches or millimeters or centimeters or meters or miles or kilometers
Answer: a
Explanation: The color of a star is linked to its surface temperature. The hotter the star, the shorter the wavelength of light it will emit. The hottest ones are blue or blue-white, which are shorter wavelengths of light. Cooler ones are red or red-brown, which are longer wavelengths.
The most probable reason why the magnets won't stick on the refrigerator is that the body of the refrigerator and the magnets have like poles. If both have negative or both have positive poles facing each other, they will repel. In principle, magnets are attracted to opposite poles and like poles repel.
Answer:
(a) 
(b) 
(c) 
Explanation:
(a) The orbital period is the time that the electron spend to travel the orbit of the atom. Thus, it is given by the length of the circular orbit divided by its velocity:
(b) Current means charge over time, So, in this case is charge over period:
(c) Magnetic moment is given by:
Here A is the area of the orbit.
