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| 373216379 | What is the devil's garden? | A bunch of Duroia hirsuta trees that are located in the South American Rainforest, and they live in a patch of land where no other trees grow. The devil's garden is basically an area protected by a colony of ants. | 0 | |
| 373216380 | What protects the Duroia hirsuta trees? | Ants that live in the hollow stems of the tree. They do not plant the trees, but instead give them room to grow. They inject intruder with poisonous chemical called formic acid. In this way, the ants create space for the growth of the Duroia trees that serve as their home | 1 | |
| 373216384 | Where did Formic Acid get its name from? | It in fact got its name from the Latin word for ant, Formica. | 2 | |
| 373216385 | What is formic acid used for by most ants? | The formic acid probably serves as a disinfectant the protects the ants against microbial parasites. The devil's garden ant is the first ant who uses it as a herbicide. | 3 | |
| 373216388 | What are organisms composed of? | Matter | 4 | |
| 373216389 | What is matter? | Matter is anything that takes up space and has a mass. | 5 | |
| 374337679 | What is matter made up of? | Elements | 6 | |
| 374337680 | What are elements? | An element is a substance that cannot be broken down to other substances by chemical reactions. | 7 | |
| 374337681 | How many elements are currently recognized as being found in nature? | 92 (e.i gold, copper, carbon and oxygen) | 8 | |
| 374337683 | What is a compound? | A compound is a substance consisting of two or more elements combined in a fixed ratio. | 9 | |
| 374337684 | Of the 92 natural elements, what percent are essential elements? | 20-25% | 10 | |
| 374337685 | What are essential elements? | They are elements that an organism needs to live a healthy life and reproduce. | 11 | |
| 374337688 | What elements make up 96% of living matter? | oxygen, nitrogen, carbon and hydrogen. | 12 | |
| 374337689 | What are trace elements? | Trace elements are required by an organism in only minute quantities. | 13 | |
| 374337690 | What trace element is needed by all sources of life? | Iron | 14 | |
| 374337691 | What happens when a human doesn't get an efficient amount of iodine? | Iodine is an essential ingredient of a hormone produced by the thyroid gland. An iodine deficiency in the diet causes the thyroid to grow to abnormal size, a condition called goiter. | 15 | |
| 374337692 | What are the Essential Elements in the human body, symbol and percentage of body mass (including water)? | Oxygen (O) 65.0% Carbon (C) 18.5% Hydrogen (H) 9.5% Nitrogen (N) 3.3% Calcium (Ca) 1.5% Phosphorus (P) 1.0% Potassium (K) 0.4% Sulfur (S) 0.3% Sodium (Na) 0.2% Chlorine (Cl) 0.2% Magnesium (Mg) 0.1% | 16 | |
| 374337694 | What is an atom? | An atom is the smallest unit of matter that still remains the properties of an element. | 17 | |
| 374337696 | What are the smaller parts of matter of an atom called? | subatomic particles. | 18 | |
| 374337697 | How many subatomic particles have been found but what are the main ones? | hundreds but the main ones are neutrons, electrons and protons. | 19 | |
| 374337698 | Are protons and electrons charged? | Yes, they are charged. | 20 | |
| 374337699 | What is the charge of a proton? | It has one positively charged unit. | 21 | |
| 374337700 | What is the charge of an electron? | It has one negatively charged unit. | 22 | |
| 374337701 | What is the charge of neutron? | It doesn't have a charge, it is neutral. | 23 | |
| 374337702 | What is an atomic nucleus? | An atom's dense central core at the center ot it, containing neutrons and protons. | 24 | |
| 374337703 | What do the electrons do? | The electrons form a sort of cloud of negative charge around the nucleus, and it is the attraction between opposite charges that keeps the electrons in the vicinity of the nucleus. | 25 | |
| 374337704 | What is about the mass of neutrons and protons (grams and daltons)? | 1.67 x 10^-27 kilograms or about 1 dalton or 1 amu | 26 | |
| 374337705 | What form of measurement is used with atoms, molecules and subatomic particles? | Daltons. In honor of John Dalton, the British scientist who helped develop atomic theory around 1800. (The dalton is the same as the atomic mass unit, or amu). | 27 | |
| 374337706 | What is the mass of electrons compared to neutrons and protons? | About 1/1840 of a proton or neutron's mass. | 28 | |
| 375273037 | What is the Atomic Number? | The number of protons and electrons in an element used to classify elements | 29 | |
| 375273038 | Where is the Atomic number written? | It is written as a subscript to the left of the symbol. | 30 | |
| 375273039 | Is an atom neutral in electrical charge and if so, what does it mean or why not? | Unless otherwise indicated, yes. It means that for every proton there is an equal number of electrons. | 31 | |
| 375273040 | What is the mass number? | It is the sum of protons plus neutrons in the nucleus of an atom. | 32 | |
| 375273041 | Where do you write the mass number? | You write it on the left side of the symbol above the Atomic number, so that the mass number is like the numerator in a fraction. | 33 | |
| 375273042 | How do you find out how many neutrons are in an element? | You minus the mass number from the atomic number. | 34 | |
| 376071090 | What are Isotopes? | Atoms of the same element that have different numbers of neutrons, and therefore have a greater mass. | 35 | |
| 376071091 | What is a Radioactive Isotope? | Isotope in which the nucleus decays (breaks down) over time, giving off radiation in the form of matter and energy | 36 | |
| 376071092 | What are atoms mostly? | Empty space. For example, let's say that the atom helium was the size of a football stadium. The nucleus would be a tiny erase in the middle of the stadium and the electrons would be two tiny gnats flying around the stadium. | 37 | |
| 376071093 | What subatomic particles are involved in chemical reactions? | Only the electrons, since the nuclei don't get close enough to interact. | 38 | |
| 376071094 | What is energy? | The capacity to cause change, especially to do work (to move matter against an opposing force). | 39 | |
| 376071095 | What is potential energy? | It is the energy that matter possesses because of its location or structure. | 40 | |
| 376071096 | What causes potential energy in atoms? | The electrons of an atom have potential energy because of how they are arranged in relation to the nucleus. The negatively charged electrons are attracted to the positively charged nucleus. It takes work to move a given electron father away from the nucleus, so the more distant an electron is from the nucleus, the greater its potential energy. | 41 | |
| 376071097 | What are electron shells? | An energy level of electrons at a characteristic average distance from the nucleus of an atom. | 42 | |
| 376071098 | How many electrons can the first shell hold? | 2 electrons | 43 | |
| 376071099 | How many electrons does the second shell hold? | 8 electrons | 44 | |
| 376071100 | What are valence electrons? | An electron in the outermost shell. | 45 | |
| 376071101 | What are valence shells? | The outermost energy shell of an atom contain the valence electrons involved in the chemical reactions of that atom. | 46 | |
| 376071102 | What is an orbital? | The 3 dimensional space where an electron can be found 90% of the time. | 47 | |
| 376071103 | Do atoms with the same number of electrons in their valence have similar chemical behavior? | Yes. For example, fluoride and chlorine both have 7 valence, and both form a compound when combined with sodium. | 48 | |
| 376071104 | What is an unreactive atom? | An atom that has a completed valence shell, that is, it will not interact readily with other atoms. | 49 | |
| 376071105 | how many electrons do each orbital contain? | 2 | 50 | |
| 376351781 | What are chemical bonds? | An attraction between to atoms, resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atom. The bonded atom gain complete outer electron shells. | 51 | |
| 376351782 | What are two strongest type of chemical bonds? | Covalent and ionic bonds. | 52 | |
| 376351783 | What are covalent bonds? | Are atoms that are sharing a pair of valence electrons. | 53 | |
| 376351784 | What is a molecule? | Two or more atoms held together by a covalent bond. | 54 | |
| 376351785 | What is electronegativity? | The attraction of a given atom for the electrons of a covalent bond. | 55 | |
| 376351786 | What is a nonpolar covalent bond? | A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity. | 56 | |
| 376351787 | What is a polar covalent bond? | A covalent bond between two atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive. | 57 | |
| 376351788 | What is a single bond? | A single covalent bond; the sharing of a pair of valence electrons by two atoms. | 58 | |
| 376351789 | What is a double bond? | A double covalent bond' the sharing of two pairs of valence electrons by two atoms. | 59 | |
| 376351790 | Name the types of ways to model molecules. | Electron Distribution Diagram (shows the electrons and shells) Lewis Dot Structure ( H:H) and Structural Formula (H-H) Space filling model (shows space, but nothing else) | 60 | |
| 380021097 | What is a valence? | the bonding capacity of a given atom; usually equals the number of unpaired electrons required to complete the atom's outermost (valence) shell. | 61 | |
| 380021098 | The more electronegative an atom is...? | The more strongly it pulls shared electrons toward itself. | 62 | |
| 380021099 | Why are the electrons in a nonpolar bond equal? | Because they have the same amount of electronegativity. The atoms are at a a tug-a-war stand-off. | 63 | |
| 380021100 | What is the most electronegative element? | Oxygen. | 64 | |
| 380021101 | What is an Ionic bond? | They are two atoms that are so unequal in their attraction for valence that the more electronegative atom strips an electron completely away from its partner. | 65 | |
| 380021102 | What is an ion? | An atom or group of atoms that has gained or lost one of more electrons, thus acquiring a charge. A charged atom. | 66 | |
| 380021103 | What is a cation? | A positively charged ion | 67 | |
| 380021104 | What is an anion? | A negatively charged ion | 68 | |
| 380021105 | What are ionic compounds? | A compound resulting from formation of an ionic bond; Also called a salt. | 69 | |
| 380021106 | What are salts? | An ionic compound. | 70 | |
| 380021107 | What is a hydrogen bond? | A weak type of chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule. | 71 | |
| 380021108 | What are van der Waals interactions? | Weak attractions between molecules or parts of molecules that result from transient local partial charges. | 72 | |
| 380021109 | What are chemical reactions? | The making and breaking of chemical bonds. | 73 | |
| 380021110 | What are reactants? | The starting materials in a chemical reaction | 74 | |
| 380021111 | What are products? | The end result of a chemical reaction. | 75 | |
| 380021112 | What do two opposite-headed arrows mean? | That the reaction is reversible. | 76 | |
| 380021113 | What are one of the factors affecting the rate of a reaction? | The concentration of reactants. The greater the concentration of reactant molecules, the more frequently they collide with one another and have an opportunity to react and form products. Same is true for products. | 77 | |
| 380021114 | chemical equilibrium | A state of balance in which the rate of a forward reaction equals the rate of the reverse reaction and the concentrations of products and reactants remain unchanged. | 78 | |
| 621814815 | What is work? | Force x Distance = Work | 79 | |
| 621814816 | What is energy measured in? | Joules | 80 | |
| 621814817 | What is the law of the conversation of energy? | Energy cannot be created or destroyed; it can be converted though (like E = MC2) | 81 | |
| 621814818 | Equation for Potential energy? | mass x gravitational acceleration x height = potential | 82 | |
| 621814819 | Equation for Kinetic Energy? | 1/2 mass x velocity ^ 2 = Kinetic | 83 | |
| 621814820 | What unit should velocity be? | miles per second | 84 | |
| 621830660 | How to classify the bonds (electronegativity)? | Difference between the electronegativity of bonds: Nonpolar Covalent Bonds: 0 - 0.2 Polar Covalent Bond: .3 - 1.4 Ionic: 1.5 and above | 85 | |
| 749284379 | What is the unit used for electronegativity? | Pauling Units | 86 | |
| 837351776 | Atom Word Origin? | Greek for Uncuttable | 87 | |
| 837351777 | What is bigger: neutrons of protons? | Neutrons are slightly bigger than protons. Protons are only 99.86% the as massive as neutrons. | 88 | |
| 2100539562 | What is the equation that determines how many electrons | 2n² and n = the level of shell. Example, the first shell would be n = 1, the second shell would be n = 2, and so on. | 89 | |
| 2100550848 | Are all chemical reactions reversible? | Theoretically all the chemical reactions are considered as reversible and said to reach equilibrium state at after some time. But in the real world, most of the reactions cannot be undone i.e. irreversible. For example, burning of wood is not a reversible reaction. | 90 |
