Concepts in Biology
atomic mass (=atomic weight)
The weight of an atomic nucleus; expressed in atomic mass units (the sum of the protons and neutrons).
relative electronegativity
determines the polarity of a molecule
non-polar covalent bond
equal sharing of electron pair; no charge separation
ionic compound
A compound that consists of positive and negative ions
polar covalent bond
A covalent bond in which electrons are not shared equally
solvent
A liquid substance capable of dissolving other substances
solution
A liquid that is a homogeneous mixture of two or more substances.
polar molecule
A molecule that has electrically charged areas.
electron
A negatively charged particle moving at a distance from the nucleus of an atom; it balances the positive charges of the protons.
chemical symbol
A one or two letter representation of an element
neutron
A particle in the nucleus of an atom that has no electrical charge.
chemical equation
A representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products
hydrogen bond
A type of weak chemical bond 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.
diatomic element
Elements that in their pure form exist in pairs
Kinetic Energy
Energy of motion
ionizing radiation
Enough energy to dislodge electrons from atoms, forming ions; capable of causing cancer (gamma, X-rays, UV), proton+neutron, a+b particles, gamma & X-rays, rodon gas from uranium
ionic bond
Formed when one or more electrons are transferred from one atom to another
element
Fundamental chemical substances that are made up of collections of only one kind of atom.
alkali metals
Group 1
Noble gases
Group 18
solute
A substance that is dissolved in a solution.
Potential Energy
Stored Energy
ductile
able to be drawn out into a thin wire.
delta minus
high electronegativity
triple bond
A chemical bond formed when atoms share three pairs of electrons
double bond
A chemical bond formed when atoms share two pairs of electrons
single bond
A chemical bond formed when two atoms share a pair of electrons
molecular compound
A chemical compound whose simplest units are molecules
non-lustrous
Nonmetals
covalent bond
A chemical bond that involves sharing a pair of electrons between atoms in a molecule
compound
(chemistry) a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight
molecule
(physics and chemistry) the simplest structural unit of an element or compound
List the chemical symbols and names of the first 20 elements.
1 - H - Hydrogen 2 - He - Helium 3 - Li - Lithium 4 - Be - Beryllium 5 - B - Boron 6 - C - Carbon 7 - N - Nitrogen 8 - O - Oxygen 9 - F - Fluorine 10 - Ne - Neon 11 - Na - Sodium 12 - Mg - Magnesium 13 - Al - Aluminum 14 - Si - Silicon 15 - P - Phosphorus 16 - S - Sulfur 17 - Cl - Chlorine 18 - Ar - Argon 19 - K - Potassium 20 - Ca - Calcium
Identify the atomic number and atomic weight of any of the first 20 elements, given a Periodic Table.
1=1.008 H 2=4.003 He 3= 6.941 Li 4=9.012 Be 5=10.81 B 6=12.01 C 7-14.01 N 8=16 O 9=19 F 10=20.18 Ne 11=22.99 Na 12=24.31 Mg 13=26.98 Al 14=28.09 Si 15=30.97 P 16=32.07 S 17=35.45 Cl 18=39.95 Ar 19=39.10 K 20=40.09 Ca
Describe the subatomic particles with respect to location, charge and mass.
3 subatomic particles: protons, neutrons and electrons.protons: positively charged, mass 1.673E, located inside the nucleus.neutrons: no electric charge, mass 1.67E, located inside the nucleus.electrons: small negative charge, mass 1.1E, located outside of the nucleus.
halogens
7A
Given a Periodic Table, identify an element as either a metal or a non-metal.
Alkali metals. The alkali metals make up group 1 of the Table, and comprise Li through Fr. They have very similar behavior and characteristics. Hydrogen is group 1 but exhibits few characteristics of a metal and is often categorized with the nonmetals. Alkaline earth metals. The alkaline earth metals make up group 2 of the periodic table, from Be through Ra. The alkaline earth metals have very high melting points and oxides that have basic alkaline solutions. Their characteristics are well described and consistent down the group. Transition metals. The transition elements are metals that have a partially filled d subshell (CRC Handbook of Chemistry and Physics) and comprise groups 3 through 12 and the lanthanides and actinides (see below). Post-transition metals. The post-transition elements are Al, Ga, In, Tl, Sn, Pb and Bi. As their name implies, they have some of the characteristics of the transition elements. They tend to be softer and conduct more poorly than the transition metals. Metalloid (or "semi-metal" or "poor metal"). The metalloids are B, Si, Ge, As, Sb, Te, and Po. They sometimes behave as semiconductors (B, Si, Ge) rather than as conductors. Lanthanides. The lanthanides comprise elements 57 (lanthanum, hence the name of the set) through 71. They are grouped together because they have similar chemical properties. They, along with the actinides, are often called "the f-elements" because they have valence electrons in the f shell. Actinides. The actinides comprise elements 89 through 103. They, along with the lanthanides, are often called "the f-elements" because they have valence electrons in the f shell. Only thorium and uranium are naturally occurring actinides with significant abundance. They are all radioactive. Nonmetals. The term "nonmetals" is used to classify the elements H, C, N, P, O, S, and Se. Halogens. The halogen elements are a subset of the nonmetals. They comprise group 17 of the periodic table, from F through At. They generally very chemically reactive and are present in the environment as compounds rather than as pure elements. Noble gases. The noble gases comprise group 18. They are generally very stable chemically and exhibit similar properties of being colorless and odorless.
polyatomic
An ion made of two or more atoms
matter
Anything that has weight (mass) and takes up space (volume).
metalloids
Are element with properties that fall between those of metals and nonmetals.
isotopes
Atoms of the same element that have different numbers of neutrons.
radioactive isotopes
Atoms that are unstable, meaning they decay, or break down, to form stable atoms of a different element
ions
Atoms with a charge
hydrophilic
Attracts water molecules
alkaline earth metals
Group 2
hydrophobic
Having an aversion to water; tending to coalesce and form droplets in water.
Period of Elements
Horizontal Row in the Periodic Table
Describe the isotopes of Hydrogen and the isotopes of Carbon (that were mentioned in class) with respect to name and subatomic particles.
Hydrogen: Protium is the most prevalent hydrogen isotope, with an abundance of 99.98%. It consists of one proton and one electron. It usually is never found in it's monoatomic form, but bonded with itself or other elements. Deuterium is a hydrogen isotope consisting of one proton, one neutron and one electron. It has major applications in nuclear magnetic resonance studies. Tritium is a hydrogen isotope consisting of one proton, two neutrons and one electron. It is radioactive, with a half-life of 12.32 years. Carbon: The important isotopes of carbon are carbon-12, carbon-13, and carbon-14. Carbon-12 contains six protons and six neutrons, carbon-13 contains six protons
Identify selected atomic structures as reactive or non-reactive. based on electron structures and the Octet Rule.
If you look at a periodic table, you see that these numbers correspond to the right hand side -- the noble gases -- these are very NOT reactive. They have a stable number of electrons and do not need to react with other atoms. All other atoms have less stable electron numbers, so they react with each other and share electrons to be more stable. The most reactive elements tend to be short one or two electron or have one or two extra. For instance, fluorine (9) and chlorine (17) are short one electron from being the most stable and they are very reactive! Sodium (11) and Potassium (19) have extra electrons and are very reactive. All the rest of the elements in between are less than perfectly stable, so they react with each other to various degrees.
Describe the formation of ionic bonds, and the formation of covalent bonds.
Ionic bonds: the formation of an ionic bond stems from the transfer of electrons from one atom to another. When such a transfer occurs, all the valence electrons on the more electropositive element (from one of the first three groups on the left in the periodic table) are removed to expose the core of the atom. The electrons so released are accepted into the empty orbitals of the valence shell of the more electronegative atom (typically from the groups immediately to the left of the noble gases); the valence shell is thereby filled. Covalent bonds: Covalent bonding includes many kinds of interaction, including σ-bonding, π-bonding, metal-to-metal bonding, agostic interactions, and three-center two-electron bonds.
3.) Use chemical formulas to write simple chemical formulas. (Potassium Sulfide) (Sodium Chloride)
K2S, NaCl
non-metals
Low conductivity, not ductile, not malleable, brittle, dull, gas at room temp
anions
Negatively charged ions
isotopic notation
Notation for an isotope of an element where the subscript is the atomic number, the superscript it the mass number, and they are attached on the left of the symbol for the element
Identify the types of bonds contained within simple molecules such as water and ammonia; and the types of bonds between water and ammonia molecules.
Notice that each water molecule can potentially form four hydrogen bonds with surrounding water molecules. There are exactly the right numbers of + hydrogens and lone pairs so that every one of them can be involved in hydrogen bonding.
cations
Positively charged ions
lustrous
SHINING
atom
The fundamental unites of matter; the smallest parts of an element that still act like that element.
Law of Conservation of Matter
The law that states that energy is never created nor destroyed.
atomic number
The number of protons in an atom.
proton
The particle in the nucleus of an atom that has a positive electrical charge.
Describe the relationship between an electron's location relative to the nucleus and its relative energy state.
The space between the nucleus and the electron is not empty space, it is filled with an electron cloud.
metals
a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity
malleable
able to be hammered or pressed permanently out of shape without breaking or cracking.
Explain an advantage and a disadvantage of water's ability to dissolve so many different substances.
advantage: regulates various life processes. disadvantage: none.
monatomic
an ion formed from a single atom
binary compound
chemical compound composed of only two elements
Group of Elements
elements that exhibit similar chemical properties; arranged in columns on the periodic table.
Describe the unusual properties of water.
if a capillary tube is made of glass or any other substance that is polar, water will spontaneously climb up inside it without having to be pumped in any way. able to absorb a lot of heat energy without having its temperature increase by very much.
delta plus
less electronegative
non-polar molecule
molecule in which the polar bonds are arranged in such a way as to cancel each other out
energy levels
the fixed energies an electron can have
Valance electrons
the number of electrons in the outermost energy level
Describe/identify the types of substances that will interact with water, and those that will not.
water dissolves many kinds of salts and sugars, many proteins, such as gelatin, and a variety of hormones that dissolve in our blood. Even non polar molecules dissolve to some extent if they are small.