Summarizing the Chemical Building Blocks
Matter is anything that occupies space and has mass. It is made up of elements. All of the 92 elements that occur naturally have unique qualities that allow them to combine in various ways to create molecules, which in turn combine to form cells, tissues, organ ...
Summary of Lessons So Far
Matter is anything that occupies space and has mass. It is made up of elements. All of the 92 elements that occur naturally have unique qualities that allow them to combine in various ways to create molecules, which in turn combine to form cells, tissues, organ systems, and organisms.
Atoms, which consist of protons, neutrons, and electrons, are the smallest units of an element that retain all of the properties of that element. Electrons can be transferred, shared, or cause charge disparities between atoms to create bonds, including ionic, covalent, and hydrogen bonds, as well as van der Waals interactions.
Glossary of Words
Anion
negative ion that is formed by an atom gaining one or more electrons
Atom
the smallest unit of matter that retains all of the chemical properties of an element
Atomic mass
calculated mean of the mass number for an element’s isotopes
Atomic number
total number of protons in an atom
Balanced chemical equation
statement of a chemical reaction with the number of each type of atom equalized for both the products and reactants
Cation
positive ion that is formed by an atom losing one or more electrons
Chemical bond
interaction between two or more of the same or different atoms that results in the formation of molecules
Chemical reaction
process leading to the rearrangement of atoms in molecules
Chemical reactivity
the ability to combine and to chemically bond with each other
Compound
substance composed of molecules consisting of atoms of at least two different elements
Covalent bond
type of strong bond formed between two of the same or different elements; forms when electrons are shared between atoms
Electrolyte
ion necessary for nerve impulse conduction, muscle contractions and water balance
Electron
negatively charged subatomic particle that resides outside of the nucleus in the electron orbital; lacks functional mass and has a negative charge of –1 unit
Electron configuration
arrangement of electrons in an atom’s electron shell (for example, 1s22s22p6)
Electron orbital
how electrons are spatially distributed surrounding the nucleus; the area where an electron is most likely to be found
Electron transfer
movement of electrons from one element to another; important in creation of ionic bonds
Electronegativity
ability of some elements to attract electrons (often of hydrogen atoms), acquiring partial negative charges in molecules and creating partial positive charges on the hydrogen atoms
Element
one of 118 unique substances that cannot be broken down into smaller substances; each element has unique properties and a specified number of protons
Equilibrium
steady state of relative reactant and product concentration in reversible chemical reactions in a closed system
Hydrogen bond
weak bond between slightly positively charged hydrogen atoms to slightly negatively charged atoms in other molecules
Inert gas
(also, noble gas) element with filled outer electron shell that is unreactive with other atoms
Ion
atom or chemical group that does not contain equal numbers of protons and electrons
Ionic bond
chemical bond that forms between ions with opposite charges (cations and anions)
Irreversible chemical reaction
chemical reaction where reactants proceed uni-directionally to form products
Isotope
one or more forms of an element that have different numbers of neutrons
Law of mass action
chemical law stating that the rate of a reaction is proportional to the concentration of the reacting substances
Mass number
total number of protons and neutrons in an atom
Matter
anything that has mass and occupies space
Molecule
two or more atoms chemically bonded together
Neutron
uncharged particle that resides in the nucleus of an atom; has a mass of one amu
Noble gas
see inert gas
Nonpolar covalent bond
type of covalent bond that forms between atoms when electrons are shared equally between them
Nucleus
core of an atom; contains protons and neutrons
Octet rule
rule that atoms are most stable when they hold eight electrons in their outermost shells
Orbital
region surrounding the nucleus; contains electrons
Periodic table
organizational chart of elements indicating the atomic number and atomic mass of each element; provides key information about the properties of the elements
Polar covalent bond
type of covalent bond that forms as a result of unequal sharing of electrons, resulting in the creation of slightly positive and slightly negative charged regions of the molecule
Product
molecule found on the right side of a chemical equation
Proton
positively charged particle that resides in the nucleus of an atom; has a mass of one amu and a charge of +1
Radioisotope
isotope that emits radiation composed of subatomic particles to form more stable elements
Reactant
molecule found on the left side of a chemical equation
Reversible chemical reaction
chemical reaction that functions bi-directionally, where products may turn into reactants if their concentration is great enough
Valence shell
outermost shell of an atom
Van der Waals interaction
very weak interaction between molecules due to temporary charges attracting atoms that are very close together
This lesson is part of:
Chemical Foundation of Life