Chemistry Key Terms

Question 1

Acid

Answer 1

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.

Question 2

Atom

Answer 2

The basic building block of a molecule that contains a nucleus and orbits.

Question 3

Atomic Mass

Answer 3

The average mass of each of that element’s isotopes.

Question 4

Atomic Number

Answer 4

The number of protons in the nucleus, and it defines an atom of a particular element.

Question 5

Base

Answer 5

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.

Question 6

Basic Unit of measure

Answer 6

Standard unit of a system by which a quantity is accounted for and expressed (grams, liters, or meters).

Question 7

Biochemistry

Answer 7

The study of chemical processes in living organisms.

Question 8

Catalysts

Answer 8

Substances that accelerate a reaction by reducing the activation energy or the amount of energy necessary for a reaction to occur.

Question 9

Celsius

Answer 9

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.

Question 10

Chemical Equations

Answer 10

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.)

Question 11

Combustion

Answer 11

A self-sustaining exothermic chemical reaction usually initiated by heat acting on oxygen and a fuel compound such as hydrocarbons.

Question 12

Compound

Answer 12

The combination of two or more elements or atoms.

Question 13

Covalent Bond

Answer 13

Two atoms share electrons, generally in pairs, one from each atom.

Question 14

Decomposition

Answer 14

A chemical reaction often described as the opposite of synthesis because it is breaking of a compound into its component parts.

Question 15

Deoxyribose

Answer 15

A sugar used in the formation of DNA.

Question 16

Double Replacement

Answer 16

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.”

Question 17

Electron

Answer 17

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.

Question 18

Electron Clouds

Answer 18

The group of electrons revolving around the nucleus of an atom; a cloud like group of electrons.

Question 19

Equilibrium

Answer 19

A state in which reactants are forming products at the same rate that products are forming reactants.

Question 20

Fahrenheit

Answer 20

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.

Question 21

Groups

Answer 21

Elements that are placed together in columns in the periodic table.

Question 22

Ionic Bond

Answer 22

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).

Question 23

Isotope

Answer 23

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.

Question 24

Kelvin

Answer 24

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.

Question 25

Mathematical Sign

Answer 25

A symbol used in mathematics. A Mathematical sign makes up one of the three parts of scientific notation and designates whether the number is positive or negative.

Question 26

Mole

Answer 26

A way to express concentrations of atoms. It is 6.02x10^23 of particles.

Question 27

Neutron

Answer 27

Part of the nucleus of an atom that has no charge.

Question 28

Nucleus

Answer 28

The positively charged

Question 29

Orbit

Answer 29

The outermost part of the atom that consists of electrons that spin around a nucleus at fantastic speeds forming electron clouds.

Question 30

Periodic Table

Answer 30

A table that organizes the elements based on their structure and thus helps predict the properties of each of the elements. It is made up of a series of rows called periods and columns called groups.

Question 31

Periods

Answer 31

A series of rows within the periodic table that classify the elements.

Question 32

pH

Answer 32

The concentrations of acids. The pH scale commonly in use ranges from 0 to 14 and is a measure of the acidity or alkalinity of a solution.

Question 33

Products

Answer 33

A substance or compound created from a chemical reaction.

Question 34

Proton

Answer 34

Part of the nucleus of an atom that has a positive electric charge.

Question 35

Reactants

Answer 35

The part of a chemical reaction that reacts to produce a desired end result or compound.

Question 36

Ribose

Answer 36

Sugar used in the formation of RNA.

Question 37

Scientific Notation

Answer 37

The scientific system of writing numbers; a method to write very big or very small numbers easily; composed of three parts: a mathematic sign(+or-), the significand, and the exponential, sometimes called the logarithm.

Question 38

Significand

Answer 38

The base value of the number or the value of the number when all the values of ten are removed. Used in scientific notation.

Question 39

Single Replacement

Answer 39

Reactions that consist of a more active metal reacting with an ionic compound containing less active metal to produce a new compound.

Question 40

Solute

Answer 40

The part of a solution that is being dissolved.

Question 41

Solution

Answer 41

A homogenous mixture of two or more substances.

Question 42

Solvent

Answer 42

The part of the solution that is doing the dissolving.

Question 43

Synthesis

Answer 43

A type of chemical reaction in which two elements combine to form a product. An example is the formation of potassium chloride (KCl) salt when a solution of potassium (K) combines with chloride (Cl-).