Answer:
The correct answer is<em><u> D. Set</u></em>
Explanation:
In contrast, <em><u>direct current</u></em> (DC) refers to a system in which the movement of electric charge in only one direction (sometimes called unidirectional flow). Direct current is produced by sources such as batteries, thermocouples, solar cells, and commutator -type electric machines of the dynamo type.
Photosyntasis Releases Oxygen Not Carbon
Therefore The Answer
Answer:
Movement of people between places on a regular basis → cyclical migration
Study of population → demographics
average number of children a woman will have in her lifetime → fertility rate
the number of people who live in a square mile or kilometer → population density
people who leave their homelands seeking safety in a foreign country → refugees
Explanation:
Migration is the movement of people from from one place to another. A cyclical migration is a kind of movement that is a routine and are usually short.
Demographics is the study of population base on age , race, gender etc.
fertility rate is said to be the measure the number of life birth of a woman in a specific period of time . Fertility rate gives information on how fertile a woman is.
Population density is the number of people per unit area. It gives information on the population per geographical area.
Refugees are individual that have been forced to live their countries to seek refuge in another country as a result of violence or persecution.
This is what I found. Raindrops form when microscopic water droplets bump into each other in clouds. the more turbulent the clouds the bigger the raindrops get
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.
