General Chemistry: Atoms First (2nd Edition) - Chapter 1 - Key Words

Element

A fundamental substance that can't be chemically changed or broken down into anything simpler.

Period (Periodic Table)

This term is used to describe each of the seven rows that make up the Periodic Table.

Group (Periodic Table)

This term is used to describe each of the eighteen columns that make up the Periodic Table.

Main groups (Periodic Table)

This term is used to describe the two larger groups on the left side and the six larger groups on the right side of the Periodic Table.

Transition metal groups (Periodic Table)

This term is used to describe the 10 smaller groups in the middle of the Periodic Table.

Inner transition metal groups (Periodic Table)

This term is used to describe the 14 groups separated off the bottom of the Periodic Table.

Property of matter

This term is used to describe any characteristic that can be used to describe or identify matter. This includes: volume, amount, odor, color, temperature.

Intensive properties

This term is used to describe characteristics of matter that do not depend on the sample size of the matter in question, ex.: melting point.

Extensive properties

This term is used to describe characteristics of matter that depend on the sample size of the matter in question, ex.: length or volume.

Physical properties

This term is used to describe characteristics of matter that do not involve a change in a given sample's chemical makeup, ex: melting point.

Chemical properties

This term is used to describe characteristics of matter that involve a change in a given sample's chemical makeup, ex: rusting or combustion.

Alkali metals (element list)

Lithium (Li), sodium (Na), potassium (K), rubidium (Rb),

and cesium (Cs) are all part of which elemental group?

Alkali metals (properties)

Each element in this elemental group is soft and silvery. They react rapidly, and often violently, in the formation of products that are highly basic. And they are highly reactive and are never found in nature in a pure state.

Alkaline earth metals (element list)

Beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra) are all members of which elemental group?

Alkaline earth metals (properties)

Each element in this elemental group is lustrous and silvery, and while reactive, are somewhat less reactive than their violent cousin of a group.

Halogens (element list)

Fluorine (F), chlorine (Cl), bromine (Br), and iodine (I) are all part of which elemental group?

Halogens (properties)

Each element in this elemental group is a colorful and corrosive metal. They are found only in combination with other elements, such as sodium.

Noble gases (element list)

Helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn) are all part of which elemental group?

Noble gases (properties)

Each element in this elemental group is colorless gas with very low chemical reactivity.

Metals (properties)

Elements of the following category are mostly silvery and shine, are malleable and ductile, and are good conductors of heat and electricity.

Nonmetals (properties)

Elements of the following category are mostly gases at room temperature. While some are colorful, none are silvery in appearance. They are poor conductors of heat and electricity. And when solid, they tend to be brittle.

Semimetals (element list)

Boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), and astatine (At) are all part of which elemental category?

Semimetals (properties)

Elements of the following category, although most are silvery in appearance and all are solid at room temperature, are brittle rather than malleable and tend to be poor conductors of heat and electricity.

Chemical compounds

This is the term used to describe two or more elements that are chemically combined.

Chemical formula

This is the term used to describe the written notation of a chemical compound.

Chemical equation

This is the term used to describe the written notation of chemical transformations.

Law of mass conservation

This is the name of the term which states, "Mass is neither created nor destroyed in chemical reactions."

Law of definite proportions

This is the name of the term which states, "Different samples of a pure chemical compound always contain the same proportion of elements by mass."

Ex) Water is always composed of hydrogen and oxygen in a 1:8 mass ratio, no matter if it comes from a tap or is formed from a chemical reaction.

Law of multiple proportions

This is the name of the term which states, "Elements can combine in different ways to form different chemical compounds, whose mass ratios are simple whole-number multiples of each other."

Ex) Carbon and oxygen form two compounds, carbon monoxide (CO) and carbon dioxide (CO₂). A fixed mass of carbon will combine with different masses of oxygen to form these compounds, and the ratio of those oxygen masses will be simple whole numbers

Theory of matter

This is the name of the term which states the following:

1. Elements are made up of tiny particles called atoms.

2. Each element is characterized by the mass of its atoms.

3. The chemical combination of elements to make different chemical compounds occurs when atoms bond together in small whole-number ratios.

4. Chemical reactions only rearrange how atoms are combined in chemical compounds; the atoms themselves do not change.

Electrons

This term is used to describe the very light-weight, negatively charged particles.

Nucleus

This is the name of the small, center portion of an atom. It contains most of the atom's mass, and contains the atom's protons and neutrons.

Protons

This is the name of the positively charged particles inside an atom's nucleus. These particles have much more mass than an atom's negatively charged particles, and are of about equal mass to an atom's neutrally charged particles.

Neutrons

This term is the name of the neutrally charged particles inside an atom's nucleus. This particles have much more mass than an atom's negatively charged particles, and are of about equal mass to an atom's positively charged particles.

Atomic Number (Z)

This term is used to describe the number of electrons around an atom's nucleus and the number of protons in an atom's nucleus.

Mass number (A)

This term is used to describe the mass of an atom or ion. It is found by adding the number of protons to the number of neutrons and is denoted by the formula, A = Z + N.

Isotopes

This term is used to describe elements with the same atomic number but different mass numbers.

Unified atomic mass unit (u)

Also known as a Dalton (d), this is the name of the term used to describe the common conversion factor of an atom's mass to grams. One of these is equal to 1.660538783 x 10⁻²⁴ g. It is considered unitless.

Atomic mass

The mass of an atom in (u) is used to describe this attribute of the given atom.

Atomic weight

This term is used to describe the weighted average of an element's atomic masses based on naturally occurring abundance.

Mole

This term is used to describe the amount of an element whose mass in grams is numerically equal to the element's atomic weight and thus contains Avogadro's number, 6.022141 x 10²³.

Molar mass

This term is used to describe the mass of a given substance divided by the amount of a given substance in the units kg/mol.

Avogadro's number

6.022131 x 10²³ atoms of any given element has a mass equal to that element's atomic weight in grams.

Nuclear chemistry

This term is used to describe the study of the properties and changes of atomic nuclei.

Nuclear equation

This is the name of the term used to describe the symbolic representation of a nucleus transformation of an atom.

Nuclear reaction

This term is used to describe a change in an atom's nucleus, usually resulting in the creation of a new element. It produces a tremendous amount of energy.

Radioactivity

This term is used to describe nuclear decay, whereby an atom's nucleus goes through a transformation that results in the emission of radiation.

Alpha (α) radiation

This term is used to describe the emission of positively charged helium nuclei during a nuclear reaction. It results in the atom's transformation into a new element, reducing its atomic number by two and it's atomic mass by four. It usually occurs in radioisotopes.

Radioisotopes

This term is used to describe, heavy, radioactive isotopes.

Nucleons

This term is the collective name for protons and neutrons

Beta (β) radiation

This term is used to describe the emission of an electron from an atom or ion after the spontaneous decay of a neutron in the nucleus of that atom or ion. It results in the atom or ion transforming into a new element, increasing its atomic number by one. It can be denoted: β⁻.

Gamma (γ) radiation

This term is used to describe very high energy, electromagnetic radiation emitted from an atom or ion and almost always occurs in conjunction with α or β radiation. It is often not shown in the writing of nuclear equations, as it does not change the atomic mass nor atomic number.

Positron emission

This term is used to describe the process by which a proton in an atom's, or ion's, nucleus decays into a neutron plus an emitted positron (β⁺). This results in the decrease of the atomic number by one, and a decrease in the atomic mass by one.

Electron capture

This term is used to describe the process by which an electron becomes trapped within the nucleus, and combines with a proton to become a neutron. This results in the decrease of the atomic number by one.