Answer:
It was the last element first discovered in nature, rather than by synthesis. Outside the laboratory, francium is extremely rare, with trace amounts found in uranium and thorium ores, where the isotope francium-223 continually forms and decays
Answer:
Sand
Explanation:
with salt distillation will work, heat the solution and collect the water in a seperate beaker
With sugar you do the same, boil away the water and collect the water vapour, you'll be left with sugar in the original container and water if you collected it
Use a fraction of column and heat the solution, the alcohol will be seperated out
Sand is the only one that uses mechanical filtration
The percentage of atoms in the universe that are hydrogen are 90%
First find the oxidation states of the various atoms:
<span>in Cr2O2 2- Cr @ +1; In NH3 N @ +3; in CrO3 Cr @ +3, N2 N @ 0 </span>
<span>Note that N gained electrons, ie, was reduced; Cr was oxidized </span>
<span>Now there is a problem, because B has NH4+ which the problem did not, and is not balanced, showing e- in/out </span>
<span>B.NH4+ → N2 </span>
<span>Which of the following is an oxidation half-reaction? </span>
<span>A.Sn 2+ →Sn 4+ + 2e- </span>
<span>Sn lost electrons so it got oxidized</span>
The first option is the correct.
Since we know the mass of one atom of Fe is 56 and that of Cl2 atoms is 71 (one atom has 35.5 mass) hence both of them will be consumed
