Question

#31

42He+27/13Al⟶?+10n

#32

Phosphorus-32 has a half-life of 14.0 days. Starting with 8.00 g of 32P, how many grams will remain after 84.0 days ?

Express your answer numerically in grams.

#33

126/52 X

Express your answer as an isotope.

#34. How many milligrams of a 40 mg sample of cesium-137 remain after 120 years ?

Express the mass to two significant figures and include the appropriate units.

#35

42He+2713Al⟶?+10n

Express your answer as an isotope or a particle.

#38. In a fission reaction, uranium-235 bombarded with a neutron produces strontium-94, another small nucleus, and 3 neutrons.

Part A Write the complete equation for the fission reaction. Express your answer as a nuclear equation.

Answer 1

₂He⁴+₁₃Al²⁷⟶₁₅P³⁰+₀n¹

32. K = 0.693/t1/2

           = 0.693/14 = 0.0495days^-1

K = 2.303/t log[A0]/[A]

0.0495 = 2.303/84 log8/[A]

log8/[A]    = 0.0495*84/2.303

log8/[A] = 1.8054

   8/[A] = 10^1.8054

8/[A]   = 63.885

   [A]    = 8/63.885 = 0.125g

33. 126/52 X

    ₅₂Te¹²⁶

34.

35.

₂He⁴+₁₃Al²⁷⟶₁₅P³⁰+₀n¹

38.

   ₉₂U²³⁵ + ₀n¹ ----------> ₃₈Sr⁹⁴   + ₅₄Xe¹³⁹ + 3 ₀n¹