Chapter 2: The Chemistry Of Life Flashcards
Matter
Anything that has mass and occupies space
Element
A pure substance with unique physical and chemical properties
Can not be broken down into other substances
Atom
Smallest unit of an element
Protons, Neutrons, and Electrons
P = positive charge E = negative charge (floating around - orbit the nucleus in electron shells) N = lack an electrical charge
Atomic nucleus
If it is positively charges it contains one or more protons and usually the same number of neutrons
Different than cellular nucleus
Atomic number
Represents the number of protons in an atom
Atomic mass number
Total number of protons and neutrons in an atom (electrons don’t count when adding up mass)
If you change the protons…
Changes the type of element
If you change the neutrons…
Slightly changes the chemical properties
ISOTOPE
If you change the electrons…
Changes the overall atomic charge
Ions
Atoms of an element that carry a net charge
Combinations of atoms make…
Molecules
Can’t be of the same lament: O(2)
Biomolecules
Carbon based
Molecules found in living cells
Subset of organic molecules
Covalent bonds
Created by the sharing of electrons between constituent atoms
Strongest bond
Single bond exists when two atoms share a PAIR of electrons
Double bond exists with when two atoms share TWO PAIRS of electrons
Covalent bonds - polar vs non-polar
Polar = has a net electrical charge, if molecule contains oxygen or nitrogen combined with any other element (unequal sharing) Non-polar = no net electrical charge (equal sharing)