A. new ocean ridges and seafloor
Answer:
The light emitted by a light bulb is a form of radiation that occurs when the filament heats up and its thermal emission gains enough energy to move into the visible spectrum.
Explanation:
Light bulbs contain a filament which is heated up electrically. When this filament is heated up,energy in the form of heat is imparted to the electrons in the filament.
This thermal excitation of electrons ultimately leads to emission of light in the viable spectrum. This light is now radiated through a light bulb.
Solve these problems like weighted averages:
The first one:
Multiply the masses (isotope numbers) by the decimal form of the percentage. Add them
0.076 (6) + 0.924 (7) = 6.924
The second one:
0.2 (10) + 0.8 (11) = 10.8
If you think about it, these answers make sense. 6.924 is much closer to 7 than to 6 (since there's a lot more lithium-7 than there is lithium-6). 10.8 is closer to 11 than to 10.