Chapter 2 Flashcards
Matter
Anything that takes up space and has mass
element
a substance that cannot be broken down to other substances by chemical reactions
compound
A substance consisting of two or more different elements combined at a fixed ratio
Trace Elements
Elements required by an organism in only minute quantities
Neutrons
Packed in atomic nucleus; Have neutral charge
Protons
Packed in atomic nucleus; Have positive charge
Electrons
orbits around the nucleus at nearly the speed of light; Has a negative charge
Dalton or Atomic Mass Unit (AMU)
The unity describing the sum of the mass of protons and neutrons in the element (Electrons are so small we do not add them into the mass of the element)
Atomic Mass Number
Number of protons in the element
Atomic Mass
The sum of the mass of protons and neutrons in an element
Isotopes
A configuration of a element where there are more neutrons than normal (Protons of a given element always have to be the same, if you add or lose a proton then the element changes)
Radioactive Isotope
An isotope whose nucleus decays and gives off particles and energy
Energy
The capacity to cause change
Potential Energy
The energy that matter possesses because of it location or structure
Energy Levels
Different states of potential energy that electrons have in an atom
Electron Shell
Shells of electron that surround the nucleus and have specific configurations
Valence Electrons
The electrons in the outer most shell of electron in an atom
Covalent Bonds
Sharing of a pair of valence electrons by two atoms
Molecule
Two or more atoms held together by covalent bonds
Single Bond
A covalent bond with a single pair of shared electrons
Double Bond
A covalent bond where TWO pairs of electrons are shared
Nonpolar Covalent Bond
When atoms bonded have SIMILAR electronegativity and electrons are moving equally around the molecule
Polar Covalent Bond
Covalent bond where atoms have DIFFERENT electronegativity values and electrons are more dense in a given area of the molecule
Ion
A charged atom
Cation
A Positively charged atom
Ionic Bond
The attraction between an ion and a cation
Hydrogen Bond
Bond formed when a Hydrogen atom bonded to one electronegative atom is also attracted to another electronegative atom
van der Waals interactions
changing “hotspots” of positive and negative charges that create a week force allowing all atoms and molecules to stick together
Chemical Reactions
The making and breaking of chemical bonds
