Answer:
Life began on Earth at least 3.5 to 4 billion years ago, and it has been evolving ever since. At first, all living things on Earth were simple, single-celled organisms. Much later, the first multicellular organisms evolved, and after that, Earth's biodiversity greatly increased.
Explanation:
Answer: Body waves travel through earths interior while surface waves travel along the earths surface. Body waves travel more rapidly than surface waves.
Explanation:
<span>Environmental protection strategies are hindered in South Asia and Southeast Asia by foreign interference. The correct option among all the options that are given in the question is the third option or the penultimate option. I hope that this answer has come to your help.</span>
More than 75 percent
Explanation:
Let us carefully analyze this problem:
The half life of the rubidium isotope = 50 billion years
The half-life of a radioactive isotope is the time it takes for it to decay to half of its original amount.
Every 50years, we know that a rubidium isotope would split into half.
Initially when the isotope was formed, we would only have the parent atoms there. There wont be any daughter;
ratio of parent to daughter = 100 : 0
When the isotope decays to half; we would have equal number of parent and daughter:
ratio of parent to daughter at half life = 50 : 50
The age of the earth is about 4.6billion years;
this is;
x 100 = 9.2% of the half-life of the rubidium isotope.
At this time, we should know that only 9.2 percent of the daughter would have been formed.
The remaining parent would be 100 - 9.2 = 90.8% would still be left undecayed.
The ratio of parent to daughter = 90.8 : 9.2
This is more than 75% of the parent
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Answer:
f. gneiss is foliated, whereas quartzite is unfoliated
Explanation:
The rock quartzite is a non foliated type of metamorphic rock. This kinds of rock has its formation caused by quartz sandstone getting metamorphic.
Metamorphic rock which are foliates such a s gneiss are formed due to heating in the earth which causes them to be soft even though they remain in the solid state. This occurs during regional metamorphism