Answer to Question 1
Hydrogen.
Answer to Question 2
Once the usable hydrogen fuel is all burned up, there remains a helium-rich core. Once fusion is finished in the star's core, there is insufficient pressure to prevent collapse due to gravity, and the contraction generates a huge increase in internal temperature, triggering a higher level of hydrogen fusion in the star's shell. The outer shell expands from the heat of accelerated fusion, but this expansion simultaneously cools the star's surface, yielding a large, cool star.
Sequence of patient positions for heart auscultation
Various views of the main body cavities.
A platinum tipped spark plug that is fuel soaked indicating a fault with the fuel system or the ...
Use a DMM set to read DC volts to check the voltage drop of the positive circuit to the fuel ...
A typical peak-and-hold fuel-injector waveform. Most fuel injectors that measure less than 6 ohms ...
The Main Macromolecules in Cells