Here we assume that disintegration has occur so the normal t½ formular will not be used
mathematically we..⅛×5600 =700
therefore it is about 700years option A
Answer:
Ba(ClO₃)₂ → BaCl₂ + 3 O₂
Explanation:
When exposed to heat, barium chlorate (Ba(ClO₃)₂ breaks down into an inorganic compound (Barium chloride - BaCl₂) and a molecule (Oxygen - O₂).
Answer: 
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The solutions in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas. Liquids are represented by (l) and gases are represented by (g).
The balanced chemical reaction is:
The valence electrons of Selenium (Se) would be placed in the s and p orbitals.
Hope I could help!
Ni solution could be used to remove lead from lead (II) nitrate.
Explanation:
The removal of lead from lead nitrate will take place by displacement reaction.
In displacement reaction less reactive element is displaced by more reactive element form it compound.
The reactivity is decided by the placement of metal in the activity series.
A metal which is at higher position in the activity series will be able to displace the metal or element having lower position.
From the options given we will check their position in the activity series in comparison to Pb
Cu is lower in series than Pb hence cannot displace.
Hg is placed lower in the series than Pb hence cannot displace Pb.
Ag is placed lower than Pb in the series hence cannot displace Pb.
Ni is placed above the Pb in activity series hence can displace lead.
