Answer:
On the placement of hydrogen and helium in the periodic system
H1=1
He2=2
Answer: 37.6 atm
Explanation:
Given that,
Initial volume of gas (V1) = 19L
Initial pressure of gas (P1) = 9.5 atm
Final volume of gas (V2) = 4.8L
Final pressure of gas (P2) = ?
Since pressure and volume are given while temperature remains the same, apply the formula for Boyle's law
P1V1 = P2V2
9.5 atm x 19L = P2 x 4.8L
180.5 atm•L = 4.8L•P2
Divide both sides by 4.8L
180.5 atm•L/4.8L = 4.8L•P2/4.8L
37.6 atm = P2
Thus, the final pressure is 37.6 atmospheres.
Let's eliminate these one by one.
The first pair would not be the same, as X would most likely be in group IA, and Y would be in group VIIA, because of their tendency to gain and lose electrons.
The second pair would also violate the same rule, but X would most likely be in group IIA, and Y would most likely be in group VIA.
The third pair would not be the same, as X is most likely in group VIIA, and since Y has eight valence electrons, it is most likely a noble gas.
The final pair has X with atomic number 15, making it phosphorous. Phosphorous wants to gain 3 electrons to have a full octet of 8 outer "valence" electrons, and Y would also like to gain 3 electrons. This means it is possible that the final pair would be in the same group.
Half life is the time that it takes for half of the original value of some amount of a radioactive element to decay.
We have the following equation representing the half-life decay:

A is the resulting amount after t time
Ao is the initial amount = 50 mg
t= Elapsed time
t half is the half-life of the substance = 14.3 days
We replace the know values into the equation to have an exponential decay function for a 50mg sample

That would be the answer for a)
To know the P-32 remaining after 84 days we have to replace this value in the equation:

So, after 84 days the P-32 remaining will be 0.85 mg
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Explanation:
Chlorine is a nonmetal because it does not have the characteristics of a metal. It cannot conduct electricity, it is not flexible, and it is not hard
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