Chapter 2 Summary Flashcards
Matter
Anything that has mass or occupies space
Atom
Basic chemical unit of matter
Element
Substance made of only one kind of atom
Molecule
compound or composed of more than one kind of atom bonded together
Atoms three basic subatomic particles
kkkljklmkl
Bohr Models
saksdakl
Atomic Number
number of protons in an atom’s nucleus (identifies kind of element)
Atomic weight
equal to the number of electrons plus the number of neutrons in the nucleus (the number of electrons equals protons in a non-ionic atom
Octet rule
an atom with 8 electrons in the outer energy level is inert
Atoms with fewer than 8 electrons
in the outer energy level will attempt to lose, gain, or share electrons with other atoms to achieve stability
Isotopes
isotopes of an element contain the same number of protons but a different number of nuetrons
Ions
Atoms (or molecules) with a charge.
H+. Ca++. OH- Cl-
Ionic Bond
Formed by a transfer of electrons.
NaCl Sodium chloride= table salt
Covalent Bond
formed by the sharing electrons (an electron pair)
Inorganic Molecules
Do not contain C-C or C-H bonds. Examples: oxygen and carbon dioxide, water, electrolytes (ions), minerals
Polarity
there are specific positive & negative charged areas around a water molecule molecule due to the position of the electrons (this allows water molecules to form hydrogen bonds [weak bonds])
Water is a great solvent
used for transportation and excretion
Water has high specific head
it can lose and gain large amounts of heat with little change in its own temperature, enables the body to maintain a relatively constant temperature
water has aHigh heat of vaporization
water requires the absorption to significant amount of heat to to change it from a liquid to a gas, allows the body to dissipate excess heat by sweating
waterIonizes easily
Water is a good buffer
minimizes pH changes in the body