Answer:
30, 50
Explanation:
Hello,
In this since an element's atomic number is equal to the number of protons in its atom, we can infer that selenium's atomic number is 30. Moreover, due to the fact the the neutrons are equal to the atomic mass minus the atomic number or the number of protons, by knowing the number of neutrons we compute the atomic as follows:

Thus, answer is 30, 50.
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Chemical reaction
equation
reactants
products
yields
mass
balanced
atoms
coefficients
numbers
element
correct
substance
two
Explanation:
did my best lol I'm like 98.69% confident
The balanced chemical reaction is:
N2 + 3H2 = 2NH3
We are given the amount of hydrogen gas to be used in the reaction. This will be the starting point of the calculations.
24.0 mol H2 (2 mol NH3 / 3 mol H2 ) = 16 mol NH3
Therefore, ammonia produced from the reaction given is 16 moles.
Answer: C the study of living things
Explanation:
Answer:
The pressure in mmHg is 1253 (option C)
Explanation:
Two quantities are directly proportional if when multiplying or dividing one of them by a number, the other is multiplied or divided by that number. In other words, the magnitudes are directly proportional when one magnitude increases and so does the other in the same proportion; or when one magnitude decreases and so does the other in the same proportion.
The rule of three or is a way of solving proportionality problems between three known values and an unknown value, which can be applied to directly proportional quantities as follows:
a ⇒ b
c ⇒ x
So 
where a, b and c are data and x is the unknown value to be calculated.
In this case, knowing that 1 Torr = 1 mmHg, the rule of three can be applied as follows: if 1 torr is equal to 1 mmHg, 1253 torr is equal to how many mmHg?

pressure= 1253 mmHg
<u><em>The pressure in mmHg is 1253 (option C)</em></u>