Answer:
5727 years or 5730 (rounded to match 3 sig figs) whichever one your teacher prefers
Explanation:
First Order decay has a half life formula of Half Life = Ln (2) / k = 0.693/K
Half-life = 0.693/k = 0.693/1.21 x10-4 = 5727 years or 5730 (rounded to match 3 sig figs)
This should be correct because if you google the half-life of 14 C it is ~ 5700 years
It would be (1) magnesium.
hope this helps :D
Answer:
The answer is D. The Sun is the closest star to Earth and so it seems brighter than distant stars that have much greater absolute brightness.
Explanation: Stars like red super giants like beetleguise are way brighter and bigger than the sun, but the sun is closest to the earth. It is only in its main sequence stage but seems bright because of its short distance from the sun( 93 million miles).