2.1 Atoms, Isotopes, Ions, and Molecules: The Building Blocks
Nucleus
A cell organelle that houses the cell's DNA
Compound
A subclass of molecules that contain more than one type of element
Periodic Table of Elements
A table that groups elements that share certain chemical properties
Hydrogen Bond
A weak bond between slightly positively charged hydrogen atoms to slightly negatively charged atoms in other molecules.
Matter
Any substance that takes up space and has mass
Ionic Bond
Bond formed between ions with opposite charges
Bohr Model
Diagram that shows the atom as a central nucleus containing protons and neutrons with the electrons in circular orbitals at specific distances from the ncleus
Noble Gases
Elements with filled outer electron shells that are un-reactive with other elements
Ions
Formed when an atom gains or looses an electron
Radioisopes
Isotopes that emit raditiaion
Anions
Negative ions formed by gaining electronsIonic
Electrons
Negatively charged subatomic particles
Chemical Reactions
Occur when two or more atoms bond together to form molecules or when bonded atoms are broken apart
Non-Polar Covalent Bonds
Occurs when the electrons are shared equally between atoms
Polar Covalent Bond
Occurs when the electrons are unevenly shared between atoms and are attracted more to one nucleus than the other
Balanced Chemical Reaction
Occurs when the number of atoms of each element is the same on either side of the equasion
Cations
Positive ions that are formed by loosing electrons
Protons
Positively charged subatomic particles
Reversable Reactions
Reactions that can go in either direction
Ireversable Reaction
Reactions that cannot be reversed (duh)
Electron Orbitals
Show how electrons are specifically distribute surrounding the nucleus; the area where an electron is likely to be found
Law of Conservation of Matter
States that the number of atoms before and after a chemical reaction should be equal because-under normal circumstances- no atoms are created or destroyed
Law of Mass Attraction
States that the rate of a reaction if proportional to the concentration of the reacting substances
Octet Rule
States that-with the exception of the innermost shell- atoms are more stable when they have eight electrons in their Valence shell
Covalent Bond
Strong bond formed between two of the same or different elements; formed when electrons are shared between two atoms
Chemical Reactivity
The ability of elements to combine and chemically bond with each other
Atomic Mass
The calculated mean of the mass number for an element's naturally occurring isotypes
Valence Shell
The outermost electron shell in an atom
Isotope
The same atom that vary only in the amount of neutrons they possess
Atom
The smallest component of matter that retains all of the chemical properties of an element.
Equillibrium
The steady state of an ecosystem where all organisms are in balance with their environment and with each other.
Atomic Number
The total amount of protons in an atom.
Mass number
The total number of particles in an atom's nucleus
Molecules
Two or more atoms chemically bonded together
Neutrons
Uncharged subatomic particles.
Elements
Unique forms of matter with specific chemical and physical properties that cannot be broken down into small substances by ordinary chemical reactions.
van der Walls Interatctions
Very weak interactions between molecules due to the temporary charges attracting atoms that are close together
