Ch.2 Chem Context of Life Flashcards
A substance consisting of two or more different elements combined in a fixed ratio
Compound
Anything that takes up space & has mass
Matter
The smallest unit of matter that retains the properties of an element
Atom
A subatomic particle having no electrical charge (neutral), w/a mass of about 1.7 x10-24g, found in the nucleus of an atom
Neutron
A subatomic particle w/a single positive electrical charge, w/a mass of about 1.7 x10-24g, found in the nucleus of an atom
Proton
A subatomic particle w/a single negative electrical charge & a mass of about 1/2,000 that of a neutron or proton. One or more electrons move around the nucleus of an atom
Electrons
The number of protons in the nucleus of an atom, unique for each element & designated by a subscript to the left of the elemental symbol
Atomic Number
The total mass of an atom, which is the mass in grams of 1 mole of the atom
Atomic Mass
One of several atomic forms of an element, each w/the same number of protons but a diff number of neutrons, thus differing in atomic mass
Isotopes
The capacity to cause change, especially to do work (to move matter against an opposing force)
Energy
The energy that matter possesses as a result of its location or spatial arrangement (structure)
Potential Energy
An electron in the outermost electron shell
Valence Electrons
A type of strong chemical bond in which two atoms share one or more pairs of valence electrons
Covalent Bonds
Two or more atoms held together by covalent bonds
Molecule
A covalent bond btwn atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative & the other slightly positive
Ex: H2O
Polar Covalent Bond
