Chemistry Key Terms Flashcards
Acid
A compound that is a hydrogen or proton donor. It is corrosive to metals, changes blue litmus paper red, and becomes less acidic when mixed with bases.
Atom
The basic building block of a molecule that contains a nucleus and orbits.
Atomic Mass
The average mass of each of that element’s isotopes.
Atomic Number
The number of protons in the nucleus, and it defines an atom of a particular element.
Base
A hydrogen or proton acceptor and generally has a hydroxide (OH) group in the makeup of the molecule. Bases are also called alkaline compounds and are substances that denature proteins, making them feel very slick; they change red litmus paper blue and become less basic when mixed with acids.
Basic Unit of measure
Standard unit of a system by which a quantity is accounted for and expressed (grams, liters, or meters).
Biochemistry
The study of chemical processes in living organisms.
Catalysts
Substances that accelerate a reaction by reducing the activation energy or the amount of energy necessary for a reaction to occur.
Celsius
A temperature system used in most of the world and in the scientific community; abbreviated C. It has these characteristics: zero degrees C is the freezing point of pure water at sea level, and 100 degrees C is the boiling is the boiling point of pure water at sea level. Most people have a body temperature of 37 degrees C.
Chemical Equations
Combination of elements or compounds called reactants responding to create a product or end result. Equations are written in the following manner: Reactants –> Products. (In some instances the arrow can go the other way or both ways.)
Combustion
A self-sustaining exothermic chemical reaction usually initiated by heat acting on oxygen and a fuel compound such as hydrocarbons.
Compound
The combination of two or more elements or atoms.
Covalent Bond
Two atoms share electrons, generally in pairs, one from each atom.
Decomposition
A chemical reaction often described as the opposite of synthesis because it is breaking of a compound into its component parts.
Deoxyribose
A sugar used in the formation of DNA.
Double Replacement
A reaction that involves two ionic compounds. The positive ion from one compound combines with the negative ion of the other compound. The result is two new ionic compounds that have “switched partners.”
Electron
A structure in an atom that is at the outermost part of the atom and has a negative charge. Electrons orbit the nucleus at fantastic speeds forming electron clouds.
Electron Clouds
The group of electrons revolving around the nucleus of an atom; a cloud like group of electrons.
Equilibrium
A state in which reactants are forming products at the same rate that products are forming reactants.
Fahrenheit
A temperature measuring system used only in the US, its territories, Belize, and Jamaica; abbreviated F. It is really used for any scientific measurements except for body temperature. It has these characteristics: 0 degrees F is the freezing point of sea water or heavy brine at sea level; 32 degrees is the freezing point of pure water at sea level; 212 degrees is the boiling point of pure water at sea level; most people have a bod temperature of 98.6 degrees F.
Groups
Elements that are placed together in columns in the periodic table.
Ionic Bond
An electrostatic attraction between two oppositely charged ions or a cation and an anion. This type of bond is generally formed between a metal (cation) and a nonmetal (anion).
Isotope
Different kinds of the same atom that vary in weight; for a given element, the number of protons remains the same, while the number of neutrons varies to make the different isotopes.
Kelvin
A unit measure for temperature that is used only in the scientific community. Kelvin (K) has these characteristics: zero degrees Kelvin (0K) is -273C and is thought to be the lowest temperature achievable or absolute zero. The freezing point of water is 273K; the boiling point of water is 373K; most people have a body temperature of 310K.
