Answer:
The correct answer out of the four given options is
option a. light elements with atomic numbers less than 5
Explanation:
Big Bang nucleosynthesis, abbreviated as BBN, also known as primordial nucleosynthesis took place after the Big Bang for about 10 s to 20 minutes and resulted in the yield of isotopes of helium-4 (
), helium-3 (
) which accounts for most of the world's helium, other isotopes of hydrogen in small amounts like deuterium (D or
) and lithium isotope, lithium-7(
) in small amount.
Apart from these stable nuclei, it also yielded two radio-active isotopes: tritium(
) and beryllium-7(
) which due to their unstability later decayed into () and ().
All of these isotopes are of light elements with atomic number less than 5.
The asthenosphere is weaker and less rigid than the overlying lithosphere.
Answer:
By sliding
Explanation:
Gracious move by a combination of deformation of the ice itself and motion at the glacier base. At the bottom of the glacier, ice can slide over bedrock or shear subgiacial sediments.
