I would have to say it would have been the 30 because thats when the moon is closet to the earth so people would be able to see the eclipse better
The answer is false.
In middle east countries, falconry is useful to Arabians way back 2000 years ago. The bird was traditionally used for hunting and it was a source of survival in the desert. The humans used its amazing ability to see great distances and to supplement their diet, catching the Habara, or similarly known as a wild turkey in the desert. That is why UAE makes the falcon as their national symbol. Camel is only used as transportation not as a means of survival.
A radioactive element with a half-life of 1,000 years, and starting mass of 20 grams, will need 2,000 years to decrease to 5 grams.
Explanation:
The radioactive elements all have a specific half-life. Each element's half-life is well known, and they are used by scientists of numerous fields as they are excellent for determining the age of a particular item, be it or organic or non-organic nature. In this case, we have a radioactive element with a half-life of 1,000 years, and starting mass of 20 grams.
The half-life basically means that half of the mass of an element is lost during a particular period of time. For the element in question we need to find out how much time will be needed for it to decrease to 5 grams. In order to get to the result, we just need to add 1,000 years on every decrease of half of the mass:
20/2 = 10
10/2 = 5
So in 1,000 years, the element in question will decrease to 10 grams, and in further 1,000 years (2,000 cumulatively) it will decrease to 5 grams.
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