Answer:

Explanation:
Given that,
The speed of light is 3×10⁸ m/s
We need to convert it into mi/hr.
Since, 1 mile = 1610 m
1 hour = 3600 s
So,

So, the required speed of light is
.
Explanation:
it's true that Lysosomes break down old and worn out cell parts....
Answer:

Explanation:
A radioactive isotope is an isotope that undergoes nuclear decay, breaking apart into a smaller nucleus and emitting radiation during the process.
The half-life of an isotope is the amount of time it takes for a certain quantity of a radioactive isotope to halve.
For a radioactive isotope, the amount of substance left after a certain time t is:
(1)
where
is the mass of the substance at time t = 0
m(t) is the mass of the substance at time t
is the half-life of the isotope
In this problem, the isotope is uranium-235, which has a half-life of

We also know that the amount of uranium left in the rock sample is 6.25% of its original value, this means that

Substituting into (1) and solving for t, we can find how much time has passed:

Atomic weights are weighted averages calculated by multiplying the relative abundance of each isotope by its atomic mass and then summing up all the products.
Two or more atoms<span> may </span>bond<span> with each other to form a molecule. When two hydrogens and an oxygen share electrons via covalent </span>bonds<span>, a water molecule is formed. Chemical reactions </span>occur<span> when two or more </span>atoms bond<span> together to form molecules or when bonded </span>atoms are broken<span> apart.</span>