Answer: C
Explanation: Really hope I can help!
Answer:
C. part 3
Explanation:
During part 3 of the cycle, water breaks the rocks apart to form sediments.
Part 3 is the erosion and weathering phase.
- Weathering is the physical disintegration and chemical decomposition of rocks to form soils.
- Water is the main agent of denudation that causes the erosion and weathering of rocks.
- Erosion carries the weathered materials from their site of disintegration.
- These sediments are then transported and deposited to form sedimentary rocks.
- people s increased exposure to ideas
- development of a increasingly global culture
The majority of Americans work in the service industry. Technology is rapidly advancing and is a high job demand. Hope this helps. ;)
Answer:
B and C
Explanation:
B. In a given rock sample, the amount of Silicon-32 isotopes gets divided in half about every 170yrs.
This is the concept of half-life. Half life is the time take for half of a radioactive isotope to disintegrate. The shorter the half life the faster the isotope disintegrates.
From the question, we were told that it would take 170yrs for half of the isotope of Silicon to disintegrate to Phosphorus. This is the half life.
C. The half life can be used to determine the amount of Si-32 that has decayed from the time closure temperature was reached.
The closure temperature is very important in radioactivity. It is the temperature at which a system has cooled and there is no resulting disintegration of parent and daughter isotopes.
From first order kinetics, we know that the rate at which radioactive elements decay at any time is directly proportional to the number of radioactive atoms present. A knowledge of the half life helps to figure out the number of atoms that has decayed in time.
