1) Matter`: the basis of life. Isotopes

Define matter

anything that occupies space and has mass, all matter is made up of elements

Define Elements

a substance that cannot be separated into simpler substances by chemical means, smallest unit of an element is an atom

Define mass number

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

Define atomic number

the number of protons in the nucleus of an atom of that element (identity of an atom)

Define isotope

atoms of an element that have the same number of protons but different numbers of neutrons

recall 4 most abundant elements found in the human body

carbon, hydrogen, oxygen, nitrogen, (CHON)

function of carbon

backbone of organic compounds

function of hydrogen

component of organic compounds; acid-base balance

function of oxygen

cellular respiration

function of nitrogen

component of protiens, nucleic acids, cell membranes

identify number of protons

atomic number

identify number of electrons

same as protons (in a electrically neutral atom)

identify number of neutrons

mass number - number of protons

discuss diagnostic applications of isotope 99Tc

• most widely used isotope in medical diagnosis

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

discuss diagnostic applications of isotope 131I

• used to detect a malfunctioning thyroid by administering a solution containing a known amount of Na(131I) and measuring the radioactivity just above the thyroid to see if the iodine is absorbed at the normal rate

discuss diagnostic applications of isotope 24Na

• used to detect blockages in the circulatory system

• in the form of 24NaCl, it is injected into the bloodstream

• traces the flow of blood and detect possible blockages

calculate relative atomic mass of elements

the average mass of an atom of the element relative to 1/12 the mass of an atom of carbon-12

• convert % abundance to fraction

• then multiply each fraction by atomic mass, then add it all together

Protons

location: nucleus

symbol: P+

charge:+1

Neutrons

location: nucleus

symbol: n

charge: 0

Electrons

location: orbits

symbol: e-

charge: -1

carbon dating

method that uses carbon-14 to estimate age of carbon bearing materials up to 58000 to 62000 years

stable isotope

does not undergo radioactive decay

molecule

an aggregate of at least two atoms (same or different) in a definite arrangement held togather by chemical bonds/forces

chemistry

study of the composition of matter, the changes it undergoes, and the energy associated with these changes

unstable isotope (radioisotopes or radionuclides)

undergoes radioactive or nuclear decay to become stable

Medical applications of radioisotopes

• diagnosing diseased states (detection)

• therapeutically treating diseased tissues (treatment)

Helium-3

• imaging of lungs

• low density of gas reduces airway resistance and promotes airflow into the lungs

Radiation therapy

• exposure to high energy radiation can induce cancer in humans and other animals

• cancer cells can be destroyed by proper radiation treatment

Radiation damage: somatic

harm that exposed individuals suffer during their life time, e.g. sunburn

radiation damage: genetic

inherited, e.g. a person whose chromosomes have been damaged/altered by radiation