Answer:
90yrs
Explanation:
Half life is the time taken for half of an original radioactive material to decay by half.
For the sample;
Half - life = 45yrs
Original amount = 600cpm
Start Number of atoms
0yrs 600cpm
First half life
45yrs 300cpm
Second half life
90yrs 150cpm
Answer:
Why ? Because 1 molecule of H2SO4 gives 2 H+ ions per molecule while only one H+ ion is required to neutralize 1 molecule of KOH. So, 1 molecule of H2SO4 can neutralize 2 molecules of KOH. Hence, we would require 525 ml of 0.03 M H2SO4 to neutralize 525 ml of 0.06 M KOH. How will we prepare 525 ml of 0.03 M H2SO4 ?
Explanation:
Now, we have 0.025 M H2SO4 and we do not know how much volume we have.
We will use the standard N1 X V1 = N2 X V2 for this calculation.
N1=0.025 M; V1=unknown; N2=0.03 M and V2=525 ml.
So V1= (0.03 X 525)/(0.025) = 630 ml.
Answer=4
Only solids can create regular geometric patterns... CO2 is a gas, H2O is a liquid and Sodium Chloride doesn't count because it's dissolved in a solution...
By doing fractional distillation
According to Avogadro's number there are 62.53 atoms of chlorine in 1.1x 10
moles of Cl atoms.
<h3>What is Avogadro's number?</h3>
Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number or number of moles×Avogadro's number.
ON substitution in above formula number of atoms=1.1×10²¹×6.023×10²³=62.53 atoms
Thus, there are 62.53 chlorine atoms in 1.1x 10
moles of Cl atoms.
Learn more about Avogadro's number,here:
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