7. Your rock sample's parent isotope has a half-life of 250 million years, If the sample contains 25% parent and 75% daughter, how old is the rock?

Age of rock = 500 million years

Explanation:

The age of the rock can be calculated by determining the number of decays (half-lives) the parent rock has undergone.

The half-life of a radioactive material is the time it takes for half the the quantity present in that material to decay or disintegrate.

The half-life of the rock sample = 250 million years

Amount of parent rock left in the rock sample = 25% = 1/4

Number of half-lives, n required is given as (1/2)ⁿ

Number of half-lives undergone by the parent rock sample to be 1/4 of the original sample is given as:  (1/2)ⁿ = 1/4

1/4 = (1/2)²

Therefore, n = 2

Age of rock = number of half-lives * half-life (in years)

Age of rock = 2 * 250 million years

Age of rock = 500 million years

children tend to take more after their grandparents more than their parents. it’s the dna you received that was passed down to you somewhere in your family. maybe one of your grandparents had/has straight hair and you might have gotten it from them.

acceleration= v2-v1/t so 8m/s-3m/s / 3s =to 8/3 or

2.67 m/s^2

hope i

-lavira: )