13.4 billion years is 3 times of the half-life, 4.47 billion years. So the Uranium-238 will go through three times of half decay. So the remain percentage will be 50%*50%*50%=12.5%.
Astronomers can measure it by way of luminosity which is the power of a star or the amount of energy (light) the star admits from its surface. they also measure the brightness of a start as if it were to appear 32.6 light years from Earth
Answer:
It's true :) Hope that helps
I believe the answer is A.
Answer:
The correct answer is from areas of high concentration to low concentration.
Explanation:
A concentration gradient exists for these molecules, so they have the potential to diffuse into (or out of) the cell by moving down it.
Hope this Helps!
