26) 89Sr - has the same valence number as calcium and will be incorporated in bone tissue if available , unfortunately 90Sr  is readily formed during above ground nuclear blasts
27) Tc - the radiaoactive form can easily created in labs (hospitals) and is used as a radioactive tracer in nuclear  medical diagnostics 
28) Ag               Cd            Sn 

29) Iodine 127 - is a key element in the production of the metabolic regulating hormone thyroxin iodine 131 can be produced and is used both to image (diagnostics)  the thyroid gland and to kill overactive (hyperthyroid) or cancerous thyroid tissue ( therapeutics)

30) Ba - salts of Barium are radio opaque and are used to image the G.I. tract with X-rays

31) Os - the heavy metal use to stain electron microscope images TEM SEM

32) Hg - toxic heavy metal used to make  tooth fillings (amalgam silver, tin, zinc, )
- lethal neurotoxin, deactivates the neurotransmitter crunching enzyme acetylcholine esterase
causing motor neurons to keep firing (spasm) in response to acetylcholine release at the synapse  A | B | C |
- Mad Hatter's disease caused by use of mercury in felt production

The Acetylcholine Synapse

Normal Transmission of Acetylcholine

ACh = Acetylcholine
E = Acetylcholinesterase
 
  1. ACh is released at the axon terminal.
  2. ACh crosses the synaptic cleft.
  3. ACh binds with a receptor on the post-synaptic membrane.
  4. AChE (E) stops the action of ACh.
Transmission with Nerve Agent Poisoning

ACh = Acetylcholine
E = Acetylcholinesterase
NA = Nerve Agent

  1. ACh is released at the axon terminal.
  2. ACh crosses the synaptic cleft.
  3. ACh binds with a receptor on the post-synaptic membrane.
  4. Nerve agents (NA) block the ability of AChE to stop the action of ACh.
  5. ACh continues to work and more ACh builds