Terms : Hide Images
| 4832453122 | matter | anything that takes up space and has me mass; matter consists of chemical elements in pure form and in combinations called compounds | 0 | |
| 4832453123 | element | a substance that cannot be broken down to other substances by chemical reactions | 1 | |
| 4832453124 | compound | a substance consisting of two or more different elements combined in a fixed ratio | 2 | |
| 4832453125 | emergent properties | a compound has chemical and physical characteristics different from those of its constituent elements | 3 | |
| 4832453126 | essential elements | elements that an organism needs to live a healthy life and reproduce; humans need 25 elements, but plants need only 17 | 4 | |
| 4832584757 | trace elements | required by an organism in only minute quantities; some trace elements such as iron are needed by all forms of life, others are required only by certain species | 5 | |
| 4832584758 | atom | the smallest unit of matter that still retains the properties of an element | 6 | |
| 4832584759 | subatomic particles | neutrons, protons, and electrons | 7 | |
| 4832584760 | proton | has one unit of positive electrical charge | 8 | |
| 4832584761 | electron | has one unit of negative electrical charge | 9 | |
| 4832584762 | neutron | electrically neutral | 10 | |
| 4832584763 | atomic nucleus | the dense core of an atom that contains protons and neutrons | 11 | |
| 4842249216 | dalton | unit of measurement used for atoms and subatomic particles | 12 | |
| 4842270741 | atomic number | the number of protons which is unique to that element | 13 | |
| 4842284127 | mass number | the total number of protons and neutrons in the nucleus of an atom | 14 | |
| 4842322402 | atomic mass | the total mass of an atom (including electrons) | 15 | |
| 4842330860 | isotopes | atoms that have more neutrons than other atoms of the same element | 16 | |
| 4842455626 | radioactive isoptope | the nucleus decays spontaneously, giving off particles and energy | 17 | |
| 4842539433 | energy | the capacity to cause change by doing work | 18 | |
| 4842554382 | potential energy | the energy that matter possesses because of its location or structure | 19 | |
| 4842615702 | electron shells | energy levels for electrons | 20 | |
| 4842663847 | valence electrons | electrons in an atoms outermost shell | 21 | |
| 4842666989 | valence shell | outermost electron shell of an atom | 22 | |
| 4843099813 | chemical bonds | attractions that hold atoms close together | 23 | |
| 4843105886 | covalent bond | the sharing of a pair of valence electrons by two atoms | 24 | |
| 4843118189 | molecule | two or more atoms held together by covalent bonds | 25 | |
| 4843132582 | single covalent bond | a pair of shared electrons | 26 | |
| 4843166760 | double covalent bond | two pairs of shared electrons | 27 | |
| 4843170429 | valence | the bonding capacity of an atom that usually equals the number of electrons needed to complete its outermost shell | 28 | |
| 4843306395 | electronegativity | the attraction of a particular atom for the electrons of a covalent bond | 29 | |
| 4843340205 | nonpolar covalent bond | the equal sharing of electrons between atoms of the same element because they have the same electronegativity | 30 | |
| 4843351248 | polar covalent bond | when an atom is bonded to a more electronegative atom (of a different element) the electrons are not equally shared | 31 | |
| 4843374729 | ions | the two resulting oppositely charged atoms (or molecules) when two atoms are so unequal in their attraction for valence electrons that the more electronegative atom strips an electron completely away from its partner | 32 | |
| 4843455110 | cation | a positively charged ion | 33 | |
| 4843458455 | anion | a negatively charged ion | 34 | |
| 4843461903 | ionic bond | the attraction between cations and anions because of their opposite charges | 35 | |
| 4843569514 | ionic compounds/salts | compounds formed by ionic bonds | 36 | |
| 4843746429 | hydrogen bonds | the noncovalent attraction when a hydrogen atom is polar covalently bonded to an electronegative atom, the hydrogen atom has a partial positive charge that allows it to be attracted to a different electronegative atom nearby | 37 | |
| 4844120270 | chemical reactions | the making and breaking of chemical bonds leading to changes in the composition of matter; cannot create or destroy atoms but can only rearrange (redistribute) the electrons among them | 38 | |
| 4844149537 | reactants | starting materials | 39 | |
| 4844150494 | products | resulting materials | 40 | |
| 4844213042 | chemical equilibrium | the point at which the forward and reverse reactions offset one another exactly; reactions are still going on, but their concentrations have stabilized at a particular ratio | 41 | |
| 4844260412 | polar molecule | the unequal sharing of electrons; the overall charge of the molecule is unevenly distributed | 42 | |
| 4844519366 | cohesion | a property of water that makes water molecules attracted to one another through hydrogen bonding | 43 | |
| 4844850161 | adhesion | the clinging of one substance to another different substance | 44 | |
| 4844895420 | surface tension | a measure of how difficult it is to stretch or break the surface of a liquid | 45 | |
| 4844924098 | kinetic energy | the energy of motion | 46 | |
| 4844927592 | thermal energy | the total kinetic energy associated with the random movement of atoms or molecules | 47 | |
| 4844930634 | temperature | the average kinetic energy of the molecules in a body of matter | 48 | |
| 4844939833 | heat | thermal energy in transfer from one body of matter to another | 49 | |
| 4844968394 | calorie (cal) | the amount of heat it takes to raise the temperature of 1 g of water by 1°C or the amount of heat that 1 g of water releases when it cools by 1°C | 50 | |
| 4844998908 | kilocalorie (kcal) | 1,000 calories is the quantity of heat required to raise the temperature of 1 kilogram (kg) of water by 1°C | 51 | |
| 4845007907 | joule (j) | an energy unit; 1 J = 0.239 cal and 1 cal = 4.184 J | 52 | |
| 4845010926 | specific heat | the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1°C | 53 | |
| 4845025952 | heat of evaporation | the quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state | 54 | |
| 4845034879 | evaporative cooling | occurs because the "hottest" molecules, those with the greatest kinetic energy, are the ones most likely to leave as gas (as liquid evaporates, the surface of the liquid that remains behind cools down (its temperature decreases) | 55 | |
| 4845056134 | solution | a liquid that is a completely homogeneous mixture of two or more substances | 56 | |
| 4845057512 | solvent | the dissolving agent of a solution | 57 | |
| 4845058202 | solute | the substance that is dissolved | 58 | |
| 4845059068 | aqueous solution | the solute is dissolved in water; water is the solvent | 59 | |
| 4845063030 | hydration shell | the sphere of water molecules around each dissolved ion | 60 | |
| 4845067135 | hydrophilic | any substance that is water-loving | 61 | |
| 4845070919 | hydrophobic | substances that are not water-loving; substances that nonionic and nonpolar (cannot form hydrogen bonds) actually seem to repel water | 62 | |
| 4847235054 | molecular mass | the sum of the masses of all the atoms in a molecule | 63 | |
| 4847311363 | mole (mol) | measures substances in units; 6.02 X 10^23 Avogadro's number | 64 | |
| 4847352096 | molarity | the number of moles of solute per liter of solution/unit of concentration | 65 | |
| 4847380017 | hydrogen ion | the nucleus of a hydrogen atom separated from its accompanying electron; the cation has a positive charge of 1 (H+) | 66 | |
| 4847396030 | hydroxide ion | a water molecule that loses 1 proton to become an anion with a negative charge of 1 (OH-) | 67 | |
| 4847434108 | hydronium ion | a hydrogen ion binds to another water molecule making it become a | 68 | |
| 4847501552 | acid | a substance that increases the hydrogen ion concentration of a solution | 69 | |
| 4847514691 | base | a substance that reduces the hydrogen ion concentration of a solution | 70 | |
| 4847535249 | acidic solution | [H+] > [OH-] | 71 | |
| 4847540677 | neutral solution | [H+] = [OH-] | 72 | |
| 4847558980 | basic solution | [H+] < [OH+] | 73 | |
| 4847644622 | pH | -log[H+] | 74 | |
| 4847670446 | buffer | a substance that minimizes changes in the concentrations of H+ and OH- in a solution (stability) | 75 |
