Sr will always have 38 protons because that is its atomic number. Normally Sr has 38 protons and 49 neutrons yielding an atomic mass of 87. unless you are dealing with an isotope of Strontium in which 3 additional neutrons would give you the 53 neutrons in your answer, (38p, 52n).
Answer: The correct answer is option (D)
Explanation:
These aurora are also known as polar lights or northern lights( north poles) or southern lights(south pole) . This is caused by the interaction between the charged particles from the sun with particles present in the upper atmosphere of the earth's atmosphere. The layer in which these interaction takes place is Thermosphere (with high temperature).
Hence, the correct answer is option (D).
Answer: ITS C OR B I THINK BUT I HAVE A FEELING ITS ONE OF THOSE
Explanation:
IM SO SORRY IF ITS WRONG KSDBDZDH
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Answer:
The length of the fence is 22.5ft and the width of the fence is 7.5ft.
Explanation:
To solve this problem we will turn this question into an equation.
The equation for the perimeter of a rectangle is 2l + 2w = perimeter.
In the question we were given the perimeter so we can go ahead and plug this in.
2l + 2w = 60
In the question we are also told that the fence is 3 times as long as it is wide. This means that 1l = 3w. We can now subsitute l for 3w so that we only have one variable.
2(3w) + 2w = 60
Now we can simply use algebra to solve for w.
6w + 2w = 60
8w = 60
w = 7.5
Now that we know the value of w we can find the value of l since we know 1l = 3w.
l = 3w
l = 3(7.5)
l = 22.5
The length of the fence is 22.5ft and the width of the fence is 7.5ft.