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Description
Flashcards by Makenna Ornes, updated more than 1 year ago
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Created by Makenna Ornes
about 3 years ago
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| Question | Answer |
| atoms | nonliving raw building materials to make livings thing -basic units of matter -smallest properties of element |
| element | pure substance, can't be broken down physically or chemically -contains only 1 type of atom |
| main 4 elements in organisms | hydrogen, oxygen, carbon, nitrogen |
| trace element & examples | one that makes up less than 0.01% of body weight -can be toxic in large amounts ex: iron, arsenic, selenium, fluorine |
| subunits of an atom | protons, neutrons, electrons |
| how many elements were created artificially by scientists? | more than 90 |
| protons | 1 or more positive charge (+1) in nucleus of atom |
| neutrons | 1 or more no charge (+/- 0) in nucleus of atom |
| electrons | usually equal to # of protons if it isn't an ion negative charge (-1) |
| atomic # | # of protons |
| mass # | sum of protons & neutrons |
| isotope | more or fewer neutrons than most common number (same # protons, diff # neutrons) -most elements have at least 2 isotopes -can be used in metabolic activities |
| radioactive isotopes | isotope with unstable nucleus which spontaneously decays to new, stable atom which then is not radioactive -stabilizes itself by emitting energy |
| radioactive decay rates can... | determine age of really old substances |
| we almost never see ________ in real life | pure elements |
| radioactive emissions can reveal... | activity of body cells which allows doctors to track disease's course without surgery |
| PET | position emission tomography - uses radioisotopes to detect tumors |
| tracer | molecule which radioisotopes are substituted for some atoms; scanner detects radioactivity (cells in cancerous tumors take up tracer faster than surrounding cells) |
| what determines if an atom will interact with other atoms? | how many electrons it has in valence shell |
| what forms molecules? | chemical bonds between atoms |
| what charges attract/repel each other? | opposite charges attract each other same charges repel each other |
| electrons that can occupy the 1st 3 shells/orbitals | 1st shell/orbital = 2 2nd shell/orbital = 8 3rd shell/orbital = 8 |
| what is simplest atom & why? | hydrogen - only has 1 electron is single shell (atomic # = 1) |
| energy levels in relation to shells | shells closest to nucleus are lowest energy level; shells further out are at higher energy level |
| atoms would rather have... | full shell of electrons than have no charge |
| chemical bond | link between atoms when electrons interact; atoms become molecules -provides stability |
| atom is most stable when... | outer shell is filled |
| inert atoms def & examples | when an atom/element has no vacancies in outer shell -don't participate in reactions/don't react with other atoms ex: helium, neon, argon |
| compound | 2 or more elements in proportions that never vary ex: CO2 |
| mixture | 2 or more kinds of molecules mingle in proportions that may or may not be the same ex: sucrose & water |
| oxidation | process in which atom/molecule loses 1 or more electrons to another atom/molecule |
| reduction | process in which an atom/molecule gains 1 or more electrons |
| when the electrons = the protons, the atom carries... | no charge |
| when atom loses an electron, charge becomes | +1 |
| when atom gains an electron, charge becomes | -1 |
| ion def | when an atom gains/loses an electron, balance between protons & electrons changes so it has a positive/negative charge |
| ionic bond def | association of two ions with opposite charges |
| covalent bond def | bond in which atoms share electrons -extremely strong & stable |
| nonpolar covalent bond | covalent bond in which atoms share electrons EQUALLY -no charge difference at the two ends -no charge across molecules ex: molecular oxygen |
| polar covalent bond | covalent bond in which atoms share electrons UNEQUALLY -atom with more protons pulls more & is slightly negative; other side is slightly positive -charge across molecules |
| usual numbers of electrons in valence shell in relation to the bond | 3, 4, 5, 6 electrons = usually covalent bond 7 electrons = ionic bond 1, 2 electrons = hydrogen bond |
| hydrogen bond def | weak link formed between a covalently bonded hydrogen & another atom in a separate covalent bond -WEAK, break easily |
| water's 6 characteristics | 1) liquid at room temp 2) good solvent 3) polar & charged 4) high specific heat 5)high heat of vaporization 6) ice is less dense than water's liquid state |
| solute; what are the spheres of hydration? | dissolved substances; when substance dissolves, water molecules cluster its individual molecules & form the spheres of hydration |
| what can dissolve in water? | anything charged |
| free radicals | any highly reactive molecule/molecule fragment having unpaired electroon |
| antioxidant | can give up 1 electron to free radical before it damages cells -found in citrus fruits & vegetables (have phytochemicals) |
| what do chemical reactions do to the body fluid? | remove and add substances |
| depending on the chemical conditions, water can... | separate into 2 ions: a hydrogen ion (H+) & a hydroxide ion (OH-) |
| what sensors are not in the body? | oxygen sensors |
| pH scale | used to measure concentration of free hydrogen ions -pH 0 is most acidic; pH 14 is most basic; pH 7 is neutral |
| each unit of change away from neutrality = ... | tenfold increase/decrease in concentration of H+ |
| blood & some other bodily fluids pH range | 7.3-7.5 |
| acid | releases H+ ions when dissolved in water -releases more H+ ions than OH- ions -pH below 7 ex: black coffee, lemon juice |
| base/alkaline fluids | accepts H+ ions when dissolved in water -releases more OH- ions than H+ ions -pH above 7 ex household bleach, dissolved baking soda |
| weak acids (acetic acid) | don't readily donate H+ but can alternate between acting as an acid or a base -can just as easily accept H+ as give it up |
| strong acids (HCl & sulfuric acid (H2SO4)) | totally give up H+ -high concentrations can be helpful in stomach but can also be hurtful |
| example of acidic situation process | eat food - stomach secretes HCl - separates into H+ |
| "acid stomach" | eat too much of certain foods |
| antacids | strong bases ex: milk of magnesia releases magnesium ions & OH- which raises fluids pH acid stomach goes away |
| salts | release ions other than H+ & OH- in solutions -form when strong acid & strong base interact |
| buffers | substances that compensate for pH changes by donating/accepting H+ |
| example of how buffers work | base added to fluid; weak acid partner gives up H+; H+ combines with OH-; forms small amount of water; doesn't affect pH |
| buffers can't make... can only... | can't make new H+ ions or eliminate ones present; can only bind or release them |
| acidosis | C02 builds up in blood & too much carbonic acid forms, pH plummets |
| alkalosis | abnormal increase in blood pH |
| blood pH homeostasis range | 7.3-7.5 pH |
| Hyperventilating | CO2 decreases so we breathe in bag so CO2 comes back in |
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