Chapter 2

Question 1

Main elements of life:

Answer 1

(96%) Carbon, Hydrogen, Oxygen, & Nitrogen

(4%) calcium, phosphorus, potassium, and sulfur

Trace elements (iodine, boron, chromium, cobalt, copper, fluorine, manganese, molybdenum, selenium, silicon, tin, vanadium, and zinc)

Question 2

Elements in human body:

Answer 2

(96.3%) Oxygen, carbon, hydrogen, nitrogen

(3.7%) Calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium

Trace elements (iodine, boron, chromium, cobalt, copper, fluorine, manganese, molybdenum, selenium, silicon, tin, vanadium, and zinc)

Question 3

Radioactive isotopes…

Answer 3

…decay spontaneously, giving off particles & energy bc they’re unstable

Question 4

“Parent” isotope decays into “daughter” isotope @ fixed rate, expressed as half-life of isotope

Answer 4

ok cools

Question 5

The electrons of an atom differ in their amounts of ______ based on their distance from the nucleus

Answer 5

…potential energy…

Question 6

An electron’s state of potential energy is called its energy level or…

Answer 6

…electron shell (farther shells = more PE)

Question 7

The chemical behavior of an atom is determined by the ______ in the electron shells (aka the # of valence electrons)

Answer 7

…distribution of electrons…

Question 8

The _______________ of molecules and ionic compounds depend on chemical bonding btwn atoms

Answer 8

formation & function

Question 9

Electronegativity?

Answer 9

an atom’s attraction for the electrons in a covalent bond (more electronegative = stronger pull of shared electrons towards itself)

Question 10

Van der Waals interaction (weak chem reaction)?

Answer 10

attractions btwn molecules that are close together as a result of the charges made by unevenly distributed electrons

Question 11

Opiates & endorphins have similar effects bc…

Answer 11

…they’re structured/composed in similar ways

Question 12

All chemical reactions are…

Answer 12

…reversible