FUNCHEM 1 (isotopes and the basis of life)

Define Matter

anything that occupies 

space and has mass. All matter is made up of elements.

Define element

s a substance that cannot be separated into simpler substances by chemical means.

Currently 118 elements have been identified.

Define atom 

is the smallest part of an element

that can undergo a chemical reaction.

Define mass number (A) 

The total number of protons and neutrons in the nucleus of an atom 

Define Atomic number (Z)

number of protons in the nucleus of an atom of that element

Define isotope 

Atoms of an element that have the same atomic number but different mass number 

same number of protons but different number of neutrons 

What are the four most abundant elements found in the human body 

Oxygen, Carbon, Hydrogen, Nitrogen

What are the funtions of the 4 most abundant elements in the human body

ComO

Oxygen	Cellular Respiration
Carbon	Backbone of organic compounds
Hydrogen	Component of organic compounds; acid-base balance
Nitrogen	Component of proteins, nucleic acids, cell membranes

How to identify number of protons, neutrons, electrons in elements

The number of neutrons in nucleus = 

Mass number – Atomic number,

 i.e. Number of neutrons = A- Z

Discuss diagnostic applications of isotopes using examples (4 of them)

Technecium-99- diagnostic is detection and the therapeutic reason is detection

Most widely used isotope in medical diagnosis.

Used to obtain images of the liver, heart, and lungs.

Gaynor, D.; Griffith, D.M. The prevalence of metal-based drugs as therapeutic or diagnostic agents: 

Beyond platinum. Dalton Trans. 2012, 41, 13239-13257.

Iodine-131 and Iodine-125 

Thyroid gland requires iodine to function properly. 

•A malfunctioning thyroid can be detected by administering a solution containing a known amount of:

•

•Na¹³¹I and measuring the radioactivity just above the thyroid to see if the iodine is absorbed at the normal rate.

•

•Na¹²⁵I and image the thyroid gland.

Sodium-24

Used to detect blockages in the circulatory system.

Sodium-24, in the form of ²⁴NaCl, 

is injected into the bloodstream as 

a salt solution.

Trace the flow of blood and detect possible blockages. The progress of blood through the arteries, veins and capillaries can be closely monitored.

Helium-3-

To obtain this image, the patient inhaled one standard litre of ³He before the MRI was taken.

Discuss radiation therapy

Exposure to high energy radiation can induce
cancer in humans and other animals.

Cancer cells can be destroyed by proper radiation treatment.

In radiation therapy, a compromise is sought

Radiation Damage

goes to somatic and genetic 

Somatic- affects the organism during its lifetime e.g. sunburn

Genetic- inherited e.g. person whose chromosomes have been damaged by radiation might have deformed offspring.

How to calculate relative atomic mass of an element

2 isotopes:  ³⁵ Cl and ³⁷ Cl

Natural abundance              Atomic Mass

³⁵ Cl                           75.77%                            34.97

³⁷ Cl                           24.23%                            36.97

Average atomic mass =   (0.7870 x 23.99) + (0.1013 x 24.99) 

                                          + (0.1117 x 25.99)

Average atomic mass = 24.31 a.m.u.

(almost like average value)

Whats a molecule

is an aggregate of at least two atoms in a definite arrangement held together by chemical forces (also called chemical bonds).

Describe mass charge and location of atoms

proton- nucleus mass of 1kg and charge of 1

neutron- nucleus mass of one kg and charge 0

electron- orbiting nucleus, 0kg and -1

What do unstable isotopes do

break down and emit radiation, energy and a particle