PLZ GIVE ME ANSWERS WITH WORK I WILL GIvE YOU A BRain LIST PL 49. Carbon-14 has a half-life of 5,730 years. If a sample contained 80 mg originally, how much
is left after 17,190 years?

50. The half-life of cobalt-60 is 5.26 years. If 100 grams are left after 15.78 years, how many
grams were in the original sample?

i only found the 49, hope it still helps, mate

49. In this question (t½) of C-14 is 5730 years, which means that after 5730 years half of the sample would have decayed and half would be left as it is.

After 5730 years ( first half life) 70 /2 = 35 mg decays and 35 g remains left.

After another 5730 years ( two half lives or 11460 years) 35 /2 = 17.5mg decays and 17.5 g remains left .

After another 5730 years ( three half lives or 17190 years) 17.5 /2 = 8.75mg decays and 8.75g remains left.

after three half lives or 17190 years, 8.75 g of C-14 will be left.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-

catya that's not even a b or c