Answer:
you will see contour elevation numbers. This is the elevation of the contour line, relative to mean sea level. Contour lines that are relatively close together indicate a slope that is fairly steep.
Explanation:
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.
Answer:
they where called wanderers because the greeks though that what we calle the planets today where actualy their gods in the form of a star so they called them wanderers after a wile they where renamed as planets the through the invention of the telosope but even though we changed them from gods to planets we still kept the name the greeks gave them.
Explanation:
