The Chemistry of Life

Flashcards about the chemistry of life

What is the simplest form of matter that can maintain unique chemical properties?

A chemical element

What two subatomic particles are used to determine atomic weight/mass?

Protons and neutrons

How is the molecular weight of a compound calculated?

By summing the atomic weights of the atoms in the compound.

What six elements account for more than 98% of an organism?

Carbon, Hydrogen, Oxygen, Nitrogen, Calcium, and Phosphorous

What percentage of human body weight do minerals constitute?

Approximately 4%

What subatomic particles are found in the nucleus of an atom?

Protons and neutrons

What determines the chemical behavior of an atom?

Valence electrons in the outermost shell

What are isotopes?

Different forms of a given element that differ in the number of neutrons and atomic mass but have the same chemical behavior.

What happens during radioactivity?

Radioisotopes decay to stable isotopes, releasing radiation.

What causes ions to carry a charge?

An unequal number of protons and electrons

What is ionization?

The transfer of electrons from one atom to another to achieve stability of the valence shell.

Name three sources of ionizing radiation.

UV light, X-rays, and nuclear decay (alpha, beta, gamma particles)

What is the physical half-life of a radioisotope?

The time needed for 50% of the radioisotope to decay.

What is the biological half-life of a radioisotope?

The time for 50% of the radioisotope to disappear from the body, dependent on the rate of decay and physiological clearance.

What are some causes of free radicals?

Normal metabolic reactions, radiation, and chemicals

what do antioxidants do?

Neutralize free radicals