How many of these battery designs involve zinc

How many of these battery designs involve zinc: Leclanche cell, alkaline, mercury, lithium-ion?

 a.
0
 b.
1
 c.
2
 d.
3
 e.
4


    
Samples of the following isotopes in pure form, each containing the same number of atoms, are taken. After one year, which sample would still contain the most atoms of the original substance?
   
 a.
sodium-24 (half-life 15 hours)
 b.
strontium-90 (half-life 29 years)
 c.
iodine-131 (half-life 8 days)
 d.
lead-210 (half-life 22 years)
 e.
thallium-206 (half-life 4 min)


The phenomenon of radioactivity was first observed by
   
 a.
Becquerel.
 b.
the Curies.
 c.
Marconi.
 d.
Roentgen.
 e.
Rutherford.