biology2

anything that occupies space and has mass

a substance that cant be broken down to other substances by ordinary chemical means

a substance consisting of two or more different elements in a fix ratio

elements that are essential to humans

ex. iron (fe) needed by all forms of life

oxygen, carbon, hydrogen, nitrogen

an iodine deficiency in the diet that causes the thyroid gland to grow to an abnormal size.

*caused when u dont ingest enough idodine

smallest unit of measure that still retains the properties of an element

proton, electron, nuetron

a subatomic particle with a single negative charge 

(-)

a subatomic particle with a single positive electrical charge (+)

*found inside the nucleus, central core

electrically nuetral has no charge

• the number of protons 
•  (top number)

sum of the # of protons and neutrons in its nucleus

(big, bottom number)

one element that has the same number of protons and behave identically in chemical reactions but have different number of neutrons 

atomic mass - atomic # = # of neutrons

• 1st shell - 2 e- (max)
• 2nd shell - 8 e- (max)
• 3rd and above - up to 18 e-

• electrons get transfered
• metal to a nonmetal 
• forms ions 
• ex. salt

an element with a charge

• electrons get shared
• nonmetal with a nonmetal
• ex. methane gas

forms when 2 atoms share their e- unequally ex. h2o creates a slightly positive side and negative side

forms when 2 atoms share their e- equally ex. methane or hydrogen gas

• the attraction with a Hydrogen atom w/ a positive charge and another atom with a negative charge 
• the polarity of water allows for hydrogen bonding

•   O-
•  /  \+ 
•       O- 
•    +/ \
•          O-
•         /  \+

• universal solvent
• expands
• high specific heat
• cohesian
• adhesion

• water is the universal solvent
• ions and polar molecules dissolve easily in water
• when solute dissolves, water molecules cluster around its ions or molecules and keep them seperated
• water transports molecules dissolved in it .

ex. blood, a water based solution, transports molecules of nutrients and wastes in organisms

water expands when it freezes

because its frozen and the colder it gets the less dense it gets

it takes alot of energy to change waters temp (due to h bonds breaking and reforming)

• important because A large body of water can absorb and store a huge amount of heat from the sun in the daytime and during summer while warming up only a few degrees. And at night and during winter, the gradually cooling water can warm the air
• The high specific heat of water also tends to stabilize ocean temperatures, creating a favorable environment for marine life.

THus because of its high specific heat, the water that covers most of Earth keeps temperature fluctuations on land and in water within limits that permit life.

• water sticking to itself
• attraction between molecules of substance
• produces surface tension in a measure of the force neccesary to stretch or break the surface of a liquid
• ex. wax paper

• water sticking to other substances
• attraction between a molecules of different substance
• ex. water on paper or glass

• 2 or more elements/compunds physically combines 
• (salt & pepper )

• solution 
• solute 
• solvent
• suspension

components are evenly distributed

substance that is dissolved

substance in which  the solute is dissolved

solution

solute

solvent

mixture of water with dissolved material

• water loving
• polar
• hydrogen bond with water
• ex glucose (sugar)

• water fearing
• nonpolar
• repelled by water (no hydrogen bonds can form)
• ex. oil

• tells us how acidic or basic a substance is
• 0-14
• 0 to 6 = acidic
• 7= neutral 
• 8 to 14 = basic
• scale measures h+ concentration of fluid 
• (the more h+ the more acidic)

ex . stomach acids, urine, hydrchloric acid, coffee, soda

ex. intestinal fluid, blood, magnesium hydroxide, bleach, salt water

weak acids or bases that can react with strong acids or bases to prevent sudden changes in PH. this is done by donating or accepting a h+ ion to or from the solution

• bicarbonate buffer system
• when blood ph rises the carbonic acid dissasosiates to from bisarbonate and h+