Problem Set #7 (The last one! J )

 10.12(c,d), 10.14, 10.26, 10.36, 10.38, 10.40(c,d), 11.14(a-c), 11.22, 11.26, 11.30, 11.40, 11.46(d-g)

 10.12

(c)   -->      +  

(d)     --->    +                   

 10.14

 After 8000 years 0.500 mg radium-226 will remain.

10.26  Ionizing radiation destroy the ability of cells to reproduce. 
Cancer is the uncontrolled proliferation of cells.  This is what causes the tumors.  
The ionizing radiation prevents the cells from dividing.  Unfortunately, the
radiation can hurt healthy cells ability to reproduce too. Ionizing radiation is
only selective in the sense that it does proportionally more damage to rapidly
dividing cells such as cancerous cells

 10.36 The three particles that can be emitted are

a. alpha particles   or a, the alpha particle is a helium nucleus.
 It is a helium atom that has been stripped of its electrons. 
Hence it has two neutrons, two protons and a charge of +2.  Because it is a relatively massive form of radiation is has a relatively low penetrating power.

b. beta particles   or b.  The beta particle is a high energy electron. 
It has small mass (1/1837 amu) and a charge of –1.  It has penetrating
power greater than an alpha particle but less than a gamma ray.

c. gamma rays  g,  the gamma ray is not a particle; it is a form of electromagnetic
radiation (just like visible light).   Gamma rays have high energy, no mass, and
penetrates very deeply. 

Note: that X-rays are similar to gamma rays, electromagnetic radiation but of lower
energy, but are not generated from radioactive decay. 

10.38     

(a)

(b)

(c)

(d)

   10.40

(c)   +

 (d)   +

  11.14    The structural formulas are as follows

(a)
(b)
(c) condensed structural formula used because of crowding

11.22    Saturated hydrocarbons contain the largest possible number of hydrogen
 in their molecular structures.  The carbons are singly bonded to other carbons
or hydrogen.  Unsaturated hydrocarbons contain fewer than the largest possible
 number of hydrogen in their molecular structures.  Some carbon are doubly or
triply bonded to other carbons.

 11.26 The structures are as follows.

(a)
	cis	trans
(b) no cis-trans isomers possible

11.30    The names and structures of the alkenes with the formula C₅H₁₀ are as follows.

1-pentene
2-pentene	cis	trans
2-methyl-1-butene
2-methyl-2-butene
3-methyl-1-butene

 11.40  the balanced equation for the complete combustion of pentane is

C₅H₁₂ + 8O₂ à 5CO₂ + 6H₂0

 11.46 Condensed structural formulas are the following.

(d)
(e)
(f)
(g)