Question 1
In the reaction

C +

He →

O how much energy is produced per gram of carbon used? Masses, in unified atomic mass units are:

C= 12.00000,

He= 4.00260,

O = 15.99491.
Express your answer in Joules/gram of carbon.
◦ 2.10 × 10
19 J/g◦ 5.76 × 10
10 J/g◦ 7.77 × 10
4 J/g◦ 2.80 × 10
11 J/g◦ 3.36 × 10
15 J/gQuestion 2
Most periodic tables indicate the elements for which all isotopes are radioactive. Which pair of elements with atomic number less than 83 have only radioactive isotopes?
◦ Pb and At
◦ Tc and Cd
◦ K and Pm
◦ Tc and Pm
◦ C and K