D. Rock type
Explanation:
The major factor that influences the strength of rocks is the rock type.
Different rock types are known to have their own relative strength.
Based on their strength, rocks are classified into hard and soft rocks.
Soft rock types are dominated by sedimentary rock. Sedimentary rocks are formed by accumulation and deposition of sediments. They are often layered.
Metamorphic and igneous rocks are usually classified as hard rocks. These rocks forms under very high temperature and pressure conditions.
In engineering applications, the soft rocks not desired for construction purposes although they have their own unique material functions.
Hard rocks are used for heavy duty and durable constructions like dams and bridges.
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Metamorphic rocks brainly.com/question/869769
Sedimentary rocks brainly.com/question/9131992
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Answer:
From the statements mentioned about Convergent Boudaries we can select the following as true.
- Convergent boundaries are where two plates move toward each other. By definition this statement is true.
- New oceanic plate (oceanic lithosphere) is created at convergent boundaries. True, a new oceanic plate can form from the action of convergent boundaries at midocean, lava and million of years do the remaining job.
- Convergent boundaries that have subduction occurring provide a "pull" force that contributes to plate motion. False, Subducting melt and ascend trough the rock creating a volcanic eruption cone and producing an island chain.
- Oceanic plates can be destroyed at convergent boundaries due to subduction. False, The older plate will subduct due to its density and it is forced deep into the mantle, it will melt once the deepth is reached.
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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Radioactive decay brainly.com/question/10125168
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