AP Bio Chapter 2, The Chemical Context of Life
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| 464608996 | Matter consists of ________ ________ in pure form and combinations called _________. | chemical elements, compounds | 1 | |
| 464608997 | An element's properties depend on... | the structure of it's atoms. | 2 | |
| 464608998 | The formation and function of molecules depend on... | chemical bonding between atoms. | 3 | |
| 464608999 | Chemical reactions make and break... | chemical bonds. | 4 | |
| 464609000 | Matter is... | anything that takes up space and has mass. *Don't confuse with weight. | 5 | |
| 464609001 | An element is... | a substance that cannot be broken down to other substances by chemical reactions. | 6 | |
| 464609002 | A compound is... | a substance containing two or more different elements combined in a fixed ratio. | 7 | |
| 464609003 | Trace elements... | are elements that are required by an organism but only in minute quantities. | 8 | |
| 464609004 | There are __ natural elements that are known to be essential to life. | 25 | 9 | |
| 464609005 | There are a total of __ natural elements. | 92 | 10 | |
| 464609006 | What are the three most common naturally occurring elements in the human body. | Carbon, Oxygen and Hydrogen | 11 | |
| 464609007 | An ____ is the smallest unit of matter that still retains the properties of an element. | Atom | 12 | |
| 464609008 | Neutrons have a charge of __; a weight in Daltons of __; and are located in the ________. | +-0; 1; Nucleus | 13 | |
| 464609009 | Protons have a charge of __; a weight in Daltons of __; and are located in the ________. | +1; 1; Nucleus | 14 | |
| 464609010 | Electrons have a charge of __; a weight in Daltons of __; and are located in the ________. | -1; 0; Electron cloud | 15 | |
| 464609011 | The atomic number is the number of _______. | Protons | 16 | |
| 464609012 | The mass number is the sum of the number of ______ & ______ and is an ___________ mass of the atom. | Protons, Neutrons, Approximate | 17 | |
| 464609013 | The atomic mass is the sum of the weight of the ______ & ______ and is an ___________ mass of the atom. | Protons, Neutrons, Total | 18 | |
| 464609014 | An isotope is... | an atom that has a different number of neutrons than the other atoms of the same element. | 19 | |
| 464609015 | A radioactive isotope is... | an isotope who's nucleus decays spontaneously, giving off particles and energy. | 20 | |
| 464609016 | Why is a radioactive isotope useful? | They can be used for medical purposes and be tracked. They also have a half-life that can be measured. | 21 | |
| 464609017 | Energy is... | The capacity to cause change. | 22 | |
| 464609018 | Potential energy is... | The energy that matter possesses because of its location or structure. Example: Roller coasters -- when they are at the top of the hill they posses a lot of potential energy due to their location. | 23 | |
| 464609019 | Potential energy that electrons have in an atom is measured by... | The energy level of the electron. Example: A ball bouncing down stairs. Each stair the ball bounces down represents an energy level lost therefore lost potential energy. | 24 | |
| 464609020 | The energy levels are made by taking... | The average distance of the electron from the nucleus. | 25 | |
| 464609021 | Energy levels are represented by... | Electron shells. | 26 | |
| 464609022 | Valence electrons are the... | Number of electrons in the outermost shell. (electrons in the furthest S and P orbitals) | 27 | |
| 464609023 | The outermost shell can be called... | The valence shell. | 28 | |
| 464609024 | The 3D space where an electron can be found 90% of the time is called a(n)... | Orbital. | 29 | |
| 464609025 | Atoms form ________ _____ to fill their valence shell. | chemical bonds | 30 | |
| 464609026 | Chemical bonds can ____ the electrons or ________ them. | Share; Transfer. | 31 | |
| 464609027 | A covalent bond is... | sharing the outermost electrons between two (or more) atoms. | 32 | |
| 464609028 | Two or more atoms held together by a covalent bond is called a(n)... | Molecule | 33 | |
| 464609029 | An electron shell diagram is... | the drawing of an atom showing it's layers of electrons and how it shares them. | 34 | |
| 464609030 | A structural diagram is... | Text based atoms showing how they share electrons using dashes and double dashes. Example: H-H or O=O | 35 | |
| 464609031 | A space filling diagram is... | a 3D representation of the molecules present. | 36 | |
| 464609032 | A single bond is... | sharing one pair of valence electrons. | 37 | |
| 464609033 | A molecular formula is... | writing out the components of a molecule. Example: H20 (pretend the 2 is a subscript.) | 38 | |
| 464609034 | A double bond is... | sharing two pairs of valence electrons. | 39 | |
| 464609035 | An atoms bonding capacity is called its... | valence. (usually the number of unpaired electrons in the valence shell -- the number needed to fill the valence shell with 8) | 40 | |
| 464609036 | Covalent bonds cause molecules to form... | electronegative charges. | 41 | |
| 464609037 | An electronegative charge... | is very weak. It gets stronger the further apart the number of valence electrons between the atoms in the molecule. | 42 | |
| 464609038 | Equal tug for electronegativity causes... | a nonpolar covalent bond. Example: O=O | 43 | |
| 464609039 | Explain polar covalent bonds. | Polar covalent bonds are caused by an unequal tug between the atoms in a molecule. Trick: Polar covalent bonds are generally symmetrical when you draw them out and cant be between two of the same atoms. Example: H2O. This gives the H's both a slightly positive charge because the Oxygen takes their electrons away -- this also gives the Oxygen a slightly negative charge. | 44 | |
| 464609040 | Cation | is a positively charged atom. | 45 | |
| 464609041 | Anion | is a negatively charged atom. | 46 | |
| 464609042 | Ion | is a charged atom. | 47 | |
| 464609043 | Ionic bonds happen between | cations and anions because of their opposite charges. The atom with the charge closest to +- 1 gives up its electrons to the other atom allowing them both to have a full valence shell. This will result in a loss of potential energy from the one that loses its electron. | 48 | |
| 464609044 | Compounds formed by ionic bonds are called _____ _________. | ionic compounds | 49 | |
| 464609045 | Ionic compounds can also be called... | salts. | 50 | |
| 464609046 | A hydrogen bond occurs between... | two oppositely electronegative molecules -- hydrogen must be one of the contributors. H2O is king at hydrogen bonding! The positive H's attract the other negative O's -- these happen really fast and only for a short time. | 51 | |
| 464609047 | Van der Waals interactions | occur when molecules are extremely close together this allows molecules to stick together. | 52 | |
| 464609048 | Molecular shape... | determines the function of the molecule. | 53 | |
| 464609049 | Chemical reactions are | the making and breaking of chemical bonds, leading to changes in the composition of matter. | 54 | |
| 464609050 | In a chemical equation the parts of the equation are called: _________ --______--> _____________ | Reactants; Reaction; Products. | 55 | |
| 464609051 | Most reactions are reversible/irreversible. | Reversible. | 56 | |
| 464609052 | Chemical equilibrium is when... | forward and backwards reactions are balanced exactly. | 57 |
