quiz 2

solid

definite shape and volume

liquid

definite volume and changeable shape

gas

changeable shape and volume

in conversions energy is lost as ___?

heat

physical elements

detected with senses

chemical elements

atom interaction

how much does mass of O,C,H,N is in our bodies?

96%

electrons

orbit around nucleus (negative charge)

atomic #

number of protons

mass #

proton + neutrons

atomic weight

average mass number of all isotops

molecule

2 atoms held together by chemical bond

compound

2 different atoms chemically bonded. Can’t be physically separated (homogenous)

mixtures

can be separated (hetero/homogenous)

reactive

unbalanced valence shell

ionic bond

gain or lose (e-): cation+anion. ex: NaCl

anion

gain (e-)= negative

cation

lose (e-)= positive

ionic example

NaCl. MgCl2. CaCl2. KCl. NaBr

covalent bond

sharing (e-)

single bond example

CH4 (methane)

covalent bond example

CH4, H2O, CO2, NH3, O2

electronegative

6 or 7 valence shell electron

electropositive

1 or 2 valence shell electron

hydrogen bonds

can’t bind atom; in dipole (H2O); surface tension in (H2O)

chemical reaction

formed when bonds are formed, rearranged, broken

combination (anabolic)

bond formation (A+B→AB)

decomposition (catabolic)

break bonds (AB→A+B): release energy

exchange

makes & breaks bonds (AB+C→AC+B)

reactant lose (e-)

electron donors; “oxidized”

reactant take (e-)

acceptors “reduced”

exergonic reaction

release energy

endergonic reaction

reaction’s products have more potential energy

organic compounds

contain carbon: covalent bond

inorganic compound

no carbon; H2O; NaCl; acid & base

organic compound examples

carbohydrates, lipids, protein, nucleic acid

carbohydrates

have carbon, hydrogen, oxygen: major function is to supply source of cellular food

carbohydrates examples

(monosaccharides)- glucose, fructose, galactose, deoxyribose, ribose

properties of H2O

high heat capacity, high heat of vaporization, polar solvent properties, reactivity, cushioning

high heat capacity

absorb and release a lot of heat before changing temperature

high heat of vaporization

liquid to gas needs a lot of heat

polar solvent properties

dissolves ionic substances form hydration layers around large charged molecules; body’s main transport medium

reactivity

important in hydrolysis and dehydration synthesis reaction

cushioning

resilient cushion around some body organs

salt

inorganic compound; contain cations (H+) and anions (OH-); electrolytes; conduct electrical currents

what can influence chemical reaction?

temperature, size, concentration, catalyst, enzyme

temperature-chemical reaction

quicker at higher

size-chemical reactions

smaller are quicker

concentration-chemical reacions

higher reacting particle concentration produce faster reactions

catalyts-chemical reactions

increase rate of reaction

enzyme-chemcial reactions

biological catalysts

acid

release (H+)= proton donors

base

release (OH-)= proton acceptors

acidic

high (H+); pH 0-6.99

alkaline

low (H+) pH 7.01-14

neutral

equal (OH-) (H+) pH 7.0