Chapter 2 Vocabulary Flashcards
Matter
Anything that has mass and takes up space.
Element
An element is a substance that cannot be broken down into smaller components by chemical reactions.
Trace Element
Elements that are required for the body in minuscule amounts
Atom
An atom is the smallest unit of an element.
Neutron
An uncharged particle in the nucleus of an atom.
Proton
A positively charged particle in the nucleus of an atom.
Electron
A negatively charged particle surrounding the nucleus of an atom, it is much smaller that the particles in the nucleus.
Atomic Nucleus
The atomic nucleus consists of both protons and neutrons.
dalton
The unit DALTON is used to measure atoms as well as other small atomic particles.
Atomic Number
The number of protons.
Mass Number
The sum of the protons and neutrons of an atom.
Atomic Weight
The average of all the isotopes.
Isotope
An isotope of an element, is that same element, only with a different number of neutrons.
Radioactive Isotope
A radioactive isotope is one in which the nucleus decays spontaneously, giving off particles and energy.
Energy
Energy is the capacity to cause change(to do work).
Energy Level
The different states of potential energy are called energy levels.
Potential Energy
Potential energy is the energy that matter posses because of location/structure.
Orbital
The 3-D space in which an electron is found most of the time(90%).
Valence Electron
The outer electrons of an atom.
Valence Shell
The outermost electron shell of an atom.
Chemical Bond
When atoms are close enough to each other, they are attracted and form chemical bonds.
Covalent Bond
A covalent bond is the sharing of a pair of valence electrons by two atoms.
Molecule
Two or more atoms held together by a covalent bond are a molecule.
Structural Formula
The structural formula represents both the atoms, and their bonding as a small diagram or chart(drawings such as: H-H).
Molecular Formula
The abbreviated way of writing the structural formula(H^2, instead of H-H)
Double Covalent Bond
When an atom shares two pairs of electrons with another atom.
Valence
The bonding capacity is called the atom’s valence, it is usually equal to the number of unpaired electrons in the outer shell.
Electronegativity
The attraction of a particular kind of atom for the electrons of a covalent bond. The more electronegative, the more strongly it pulls the electrons toward itself.
Nonpolar Covalent Bond
When a pair of electrons are shared evenly between two atoms.
Polar Covalent Bond
When a pair of electrons are shared unevenly between two atoms.
Ion
A charged atom is called an ion.
Cation
A positively charged atom.
Anion
A negatively charged atom.
Ionic Bond
When two ions of opposite charge form a bond.
Hydrogen Bond
A hydrogen bond forms when hydrogen bonds to a highly electronegative atom. H2O
Chemical Reactions
The making and breaking of chemical bonds resulting in changes in the composition of matter are called chemical reactions.
Reactants
The starting material(s)
Products
The materials resulting from the reaction.
Chemical Equilibrium
The point at which the reactions offset one another exactly is called chemical equilibrium.
