After two half-lives or 60 years, 7.5 g of the element will be left.
<u>Explanation:</u>
<u>Half-life:</u>
- In simple words, Half-life can be defined as the amount of time needed for a quantity to fall to half its value as contained at the beginning of the time period.
- In this problem the half-life of the element is thirty years, then after thirty years half of the sample would have decayed and half would be left as it is.
- After thirty years (The first half-life ) 30 /2 = 15 g declines and 15 g remains disappeared.
- And after another sixty years (The two half-lives) 15 /2 = 7.5 g declines and 7.5 g remains disappeared.
- After two half-lives or 60 years, 7.5 g of the element will be left.
Answer:
Can I get brainiest answer Mitochondria Lysosomes vacuole
Given what we know, we can confirm that the scandal committed by the Secretary of the Interior who worked under President Taft was that he sold Alaskan coal lands that were supposed to be national parks.
<h3>Why is this important?</h3>
National parks are the way in which the government can preserve lands and protect the conservation of the organisms that inhabit those lands. The selling of these lands marked a major scandal at the time as they were considered shady dealings, shrouded in secrecy, that undermine conservative efforts.
Therefore, we can confirm that the answer is C, as he sold the Alaskan coal lands that were supposed to be protected national parks.
To learn more about national parks visit;
brainly.com/question/2510693?referrer=searchResults
Answer: volcanoes
Explanation: geothermal electricity- generating plants are most commonly located around the Ring of Fire, which is a hotspot for volcanoes.
The correct answer is (d.) proteins. Higher organisms use nitrogen to make their protein. Food that is containing protein also involves nitrogen in it. Protein also has amino acids that contain nitrogen in it which is a necessary essential nutrient for the body.
