Massive stars fuse hydrogen, then helium, and finally develop carbon-oxygen cores. At about 1 billion K, they are able to ignite carbon, then oxygen, neon and magnesium fuse to make silicon, and finally iron. Because more and more protons are used up to make
heavier atoms, we could expect
A)
less energy to be emitted from the star.
B)
more energy to be emitted due to fusion
the production of more radioactive isotopes
D
more electromagnetic radiation to be emitted.
Atomic Theory and Periodic Law

Which radioisotope is used to date fossils? a. oxygen-16 b. carbon-14 c. uranium-238 d. carbon-12

What is the difference between covalent bonds and ionic bonds? covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms. covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of electrons between atoms. covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms. covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged atoms.

El amoniaco y el fluor reaccionan para formar tetrafluoruro de dinitrogeno y fluoruro de hidrogeno. segun la reaccion: nh3 + f2 ⇒ n2f4 + hf si reaccionan 5 gramos de amoniaco y 20 gramos de fuor, ¿cuantos gramos de fluoruro de hidrogeno se producen?