Seafloor of the Galveston is full of sand and sediment which is suspended in and around the bay.
<u>Explanation:</u>
The water in and around the Galveston bay. The reason for the water to be brown in that area is because of the sediments and other material which are suspended to be brown in the water.
The water in the Galveston is shallow as a reason of which the sediments and the sand turn over in that area is high, making it look brown in color instead of blue. Thus water seems to be dirty and muddy at many point of time.
The mission of the U.S. Fish & Wildlife Service is to "working with others to conserve, protect, and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people."
Answer:
1.- b. when the Moon is at right angles to the direction of the Sun.
2.-b. when the Moon is directly opposite the position of the Sun.
3.-b. when the Moon is closer to the Sun than the Earth is.
Explanation:
- The First Quarter Moon is when we can see exactly half of the Moon's surface illuminated. If it is the left or right half, it depends on where you are on Earth. If we observe the diagram I added we can see than <em>the moon is at right angles to the direction of the Sun</em> when it's in this phase.
- Full Moon happens when<em> the Moon is on the opposite side of the Earth from the Sun</em>, this makes the bright side of the Moon face the Earth. This is also observable in the diagram.
- The New Moon always occurs when <em>the Moon is between the Earth and the Sun, therefore it's closer to the Sun than the Earth</em>, the bright side of the Moon is facing away from the Earth. You can check this in the diagram as well.
I hope you find this information useful and interesting! Good luck!
Answer:
The age of the rock = 2800.6 million years = 2.8 billion years.
A simple method of analysis similar to Carbon dating is used to obtain the required age of the rock. Radioactive substances decay according to first order reaction kinetics. So, plugging all the required parameters into the general equation for amount of substance left in a first order decay gives us the age of the rock.
Explanation:
Half life of Uranium-235 = 700 million years (from literature)
The decay of radioactive substances follow first order reaction kinetics.
The general equation is given as
A(t) = A₀ e⁻ᵏᵗ
A(t) = Amount of radioactive substance left after a particular time = 6.25%
A₀ = initial amount of radioactive substance = 100%
t = time that has passed since the beginning = age of the rock = ?
k = decay constant
The decay constant is related to the half life (T) through the relation,
k = (In 2)/T
k = (0.693/700) = 0.00099 /million years
A(t) = A₀ e⁻ᵏᵗ
6.25 = 100 e⁻ᵏᵗ
0.0625 = e⁻ᵏᵗ
In e⁻ᵏᵗ = In 0.0625 = -2.7726
-kt = - 2.7726
t = (2.7726/0.00099) = 2800.6 million years
t = 2.8 billion years.
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