If air is 80% N15 and 20% O16. Using the data below, calculate the average distance a thermal neutron travels in air before having an interaction. Air density = 1.202 gm/cm3 %3D 016 atomic wt = 15.994 gm N15 atomic wt 14.0067 gm N15 total microscopic cross o16 total microscopic cross section = 4.03 b 12.20 b %! section %3D

What is the activity of a sample of C that contains 6.7x1020 nuclei? The half-life of C is 5700 years. Express your answer using two significant figures. Te

5 Answer the following questions: a) For a homogeneous nucleation process, sketch the dependence of the surface and bulk free energies on the radius of a spherical embryo using the equation below. kT AG, = 4rv*y -* inS V, AG > r b) Sketch the dependence of the free energy changes (AG,) on the radius of a spherical embryo when the supersaturation ratio (S) is greater than 1, equal to 1 and less than 1. AG c) Discuss the importance of supersaturation on precipitation

Calculate the energy released in the reaction, in MeV: 6Li + n = 4He + 3H mLi = 6.015123 u; mn = 1.008665 u; mHe = 4.002603 u; mH = 3.016049 u %3D %3D

Find how many neutrons are in the following real or imaginary nuclei that are represented in the form ZXA: (a)79X180, (b)15X30, (c)6X12, (d)90X199.

An unknown element X has the following isotopes: ⁶⁴X (49.00% abundant), ⁶⁶X (28.00% abundant), ⁶⁸X (23.00% abundant). What is the average atomic mass in amu of X?

The gold nucleus has a mass of 3.27 × 10–25 kg. What is the density of the nucleus (in g cm–3)?   2.7 × 1014   3.5 × 1014   1.4 × 1014

Disintegration. NUCLEAR PHYSICS. Explain what it's being used. It has been found that a sample of uranium oxide (U308), freshly prepared from an ore of uranium, emits 20.5 a particles per mg per second. If we have A238 = 4.8 × 10¬185-1, is it possible to have a 1mg sample?

Question 04 The moderator temperature coefficient for a reactor is -8.2 pcm/ F. Calculate the reactivity defect that results from a temperature decrease of 5° F. Px = (Ax)(ax)

Compute the approximate nuclear radius of: U (ن) (d) Nit -12 I allatiun c Actinium-89