Unit 3 Vocab

Front 1

Atom: The atom is the smallest unit that defines the chemical elements and their isotopes. Every material object, or substance that can be touched and felt, is made up of atoms. Everything that is solid, liquid, or gas is made up of atoms.

Back 1

Hint 1

Example: everything is made of atoms

Front 2

Atomic mass: the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.

Back 2

Hint 2

Example: the atomic mass of carbon is 12 amu

Front 3

Atomic mass unit: a unit of mass used to express atomic and molecular weights, equal to one-twelfth of the mass of an atom of carbon-12. It is equal to approximately 1.66 x 10-27 kg.

Back 3

Hint 3

Example: the atomic mass unit of an element is in the top right corner of their box on the periodic table

Front 4

Atomic number:
the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.

Back 4

Hint 4

Example: the atomic number of hydrogen is 1

Front 5

Atomic symbol: the same thing as a chemical symbol, just with more information

Back 5

Hint 5

Example: most atomic symbols include the mass and atomic number of the element

Front 6

Chemical symbol: A chemical symbol is a code for a chemical element. It is usually derived from the name of the element, often in Latin. This is an example of an atomic symbol. The text boxes explain where the numbers are derived from.

Back 6

Hint 6

Example: the chemical symbol for hydrogen is H

Front 7

Electron:
a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.

Back 7

Hint 7

Example: electrons are found in the outer shells of the atom

Front 8

Group: In chemistry, a group (also known as a family) is a column of elements in the periodic table of the chemical elements. There are 18 numbered groups in the periodic table, but the f-block columns (between groups 2 and 3) are not numbered.

Back 8

Hint 8

Example: group one includes all the above elements

Front 9

Isotope:
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.

Back 9

Hint 9

Example: there are three isotopes of hydrogen

Front 10

Mass number: the total number of protons and neutrons (together known as nucleons) in an atomic nucleus.

Back 10

Hint 10

The mass number of potassium is 39

Front 11

Metal:
a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity

Back 11

Hint 11

Example: iron, gold, silver, copper, and aluminum, and alloys such as brass and steel)

Front 12

Metalloid:
an element (e.g., germanium or silicon) whose properties are intermediate between those of metals and solid nonmetals. They are electrical semiconductors.

Back 12

Hint 12

Example: germanium or silicon

Front 13

Neutron:
a subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen.

Back 13

Hint 13

Example: oxygen has 8 protons

Front 14

Nonmetal:a chemical element that mostly lacks metallic attributes.

Back 14

Hint 14

Examples: helium neon argon

Front 15

Nucleus: the positively charged central core of an atom, consisting of protons and neutrons and containing nearly all its mass.

Back 15

Front 16

Period: A period is the name given to a horizontal row of the periodic table. The periodic table has seven periods. Period 1 contains only two elements: hydrogen and helium.

Back 16

Hint 16

Example: the first period contains hydrogen and helium

Front 17

Proton:
a stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but of opposite sign.

Back 17

Hint 17

Example: an atom of hydrogen has one proton

Front 18

Subatomic particle: a particle smaller than an atom or a cluster of such particles

Back 18

Hint 18

Example: a neutron