Chapter 2 Flashcards
The Chemical Foundations of Life
Define Biology
Study of life
Matter
any substance that occupies space and has mass
Element
unique forms of matter with specific chemical and physical properties that can not be broken down into smaller substances by normal chemical reactions
Atom
the smallest unit of matter that retains all of the chemical properties of an element
Molecule
two or more atoms chemically bonded
Compound
atoms of more than one type of elements chemically bonded
Ion
an atom that has gained or lost electrons causing them to develop charges
Cation
positive ions formed from losing electrons
Anion
negative ions formed from gaining electrons
Electron Transfer
movement of electrons from one element to another
Reactant
substances used in the beginning of the reaction
Product
substances found at the end of the reaction
Be able to name several properties that are common to all life.
Name the four elements common to all living organisms.
Carbon, oxygen, hydrogen, nitrogen
The structure of an atom – the nucleus and the outer electron shells
Nucleus-the center of the atom that has protons and neutrons
Electron shells- orbit the nucleus, holds electrons
Distinguishing characteristics of protons, neutrons, and electrons and where each is located.
Protons- in the nucleus, one Dalton, positive charge
Neutrons- in the nucleus, one Dalton, neutral/no charge
Electrons-orbit nucleus, insignificant mass, negative charge
Atomic number of an element, and the ratio of protons and electrons in a neutral atom.
Atomic number is number of protons, in a neutral atom, the number of electrons is equal to the number of protons
Who developed the atomic theory and in what year?
Niels Bohr in 1913
The nature of the sub-levels (s, p, d, f) of energy shells (1, 2, 3, 4, etc), and how the order the sub-levels fill help determine the likelihood of atomic bonding. (If required for the exam, you will be given the fill order of sub-levels (1s2; 2s2, 2p6; 3s2, 3p6, 4s2, 3d10; 4p6, etc.)
First fill the shells closest to the nucleus, the outermost shell determines the stability and likelihood to form bonds **Most stable when the outermost shell is full
How the electron configuration determines which types of bonds will be likely to form (electron donated, accepted, shared? How many?).
If the atom has half or more of it shell filled, it will accept until it is full; if less than half is full, it will donate; sharing occurs between two nonmetals that have most of their shell filled
The differences between ionic, covalent, and hydrogen bonds, including how they are formed and their relative strengths.
Ionic bonds-donating and accepting of electrons
Covalent bonds-sharing of electrons; relatively stronger
Hydrogen bonds-partial charges made by covalent bonds; commonly the strongest
The difference between single, double, and triple covalent bonds.
The more bonds=the higher melting point and closer the atoms are
The difference between polar and non-polar covalent bonds.
In nonpolar bonds-the two atoms that are sharing are doing so equally while in polar bonds, on atom is pulling the electron and creating a partial negative on itself
Discuss life-sustaining properties of water such as cohesion, adhesion, and as potent solvent.
Cohesion-the water molecules are bound to other water molecules and create surface tension
Adhesion-allows water to spontaneously move up the side of a glass or into a capillary tube
Solvent-is easily able to dissolve other things
What is a “hydration shell”
The water molecules surround the solute and the charge of the solute particle determines what side of the water molecule attaches to it; water is then able to dissolve the solute
Discuss the atomic structure of carbon that makes it an ideal structural backbone of life.
Carbon has four electrons which makes it able to bond to four other molecules to fill its outer shell; this allows for the building of chains; it also forms strong covalent bonds
