It is mostly about an element, it usually goes like this: "which element has the bigger atomic size, Sodium or Oxygen? "
Half life of a radio-active material is refereed to the time required for reducing its activity to 50 %.
Now, when I-131 passes 1st half life, it's activity will reduce to half i.e. 50%
When, I-131 passes 2nd half life, activity of I-131 will be reduced to 25%
On passing, 3rd half-life, percent activity of the I-131 <span>remaining will be 12.5 %.</span>
Answer:
3.840 atm
Explanation:
We use Boyle's law, which relates the pressure (P) and the volume (V) of a gas at a constant temperature. The change from initial P and V (P₁ and V₁) to final P and V (P₂ and V₂) is expressed as:
P₁V₁ = P₂V₂
We have the following data:
P₁= 0.960 atm
V₁= 200.0 mL
V₂ = 50.0 mL
Thus, we introduce the data in the equation and calculate the final pressure P₂:
P₂ = P₁V₁/V₂= (0.960 atm x 200.0 mL)/50.0 mL = 3.840 atm
Therefore, a pressure of 3.840 atm is needed to reduce the volume of the gas from 200.0 mL to 50.0 mL.
<span>Displaced volume:
final volume - initial volume :
38.55 mL - 15.75 mL = 22.8 mL
D = m / V
D = 32.138 / 22.8
D = 1.409 g/mL
hope this helps!
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He discovered choice C! this is because atoms of the same element can have different numbers of neutrons
