Answer:
look care fully and read it
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:
volcanoes and rivers
Explanation:
the salt from the ocean come from fresh water rivers , and volcanic eruptions spew out water vapor and and carbon dioxide and other gasses like chlorine. the chlorine will then dissolve into the ocean and combine with sodium to get sodium chloride.
I hope this help you, have a wonderful day.
Answer:
During Earth's orbit in the summer months, the top of the Earth (the Northern Hemisphere) is tilted toward the sun, giving us longer days. In winter, the Northern Hemisphere points away from the sun, resulting in fewer hours of sunshine and shorter days
Explanation:
Answer:
They can collect some marine objects like shells and also the fresh winds are due to the physical features.
Explanation:
Waves, tides and currents are the responsible to the erosion in coastal areas, this physical feature will give some benefits to the people there because the movement of the waves can bring to the beach some shells to sell or some crabs to eat.
Also coast are dynamics, that mean, that they move faster in their content, giving some reasons to visit the beaches as touristic places.
Waves and tides of coast also can be attractive for some boats (or practicing sailing) or other aquatic sports like surf.
Hope this information is useful.
