U 5a Atoms, Elements and PT

S8P1a, S8P1e

atom

The atom is a basic unit of matter and the smallest unit of an element. It consists of a nucleus which is surrounded by a cloud of electrons.

Alkali metals

The alkali metals are the elements in the first column of the periodic table with the exception of hydrogen.

Alkaline earth metals

The alkaline earth metals are the elements in the second column of the periodic table.

Compound

A chemical compound is a pure substance made up of two or more elements (H2O)

Distillation

The process of separating mixtures by boiling a liquid and then recovering the cooled gas.

Ductile

The ability of a material to be stretched into a long wire.

Electron

A particle of an atom that orbits the atom's nucleus and carries a negative charge, no atomic weight

Element

A pure chemical substance that is made up of one type of atom. Each atom in an element is defined by an atomic number which is the number of protons in the nucleus

Ion

An atom or molecule which has a negative or positive charge because the number of electrons does not equal the number of protons.

Malleable

A substance is said to be malleable if it can be pounded into a thin sheet.

Metal

A substance that is a good conductor of heat and electricity. They are generally malleable, ductile, and shiny.

Mixture

A combination of two or more substances that are not chemically combined.

Molecule

A molecule is formed when two or more atoms are joined together by a chemical bond

Neutron

A particle in the nucleus of an atom that has no electric charge, atomic mass of 1 amu

Noble gases

A family of elements that makes up column 18 of the periodic table. They are very stable due to their full outer electron shells.

Nucleus

The central core of an atom containing the protons and neutrons.

Periodic table

A table of the chemical elements arranged by atomic number.

Proton

A particle within the nucleus of an atom that holds a positive charge, atomic mass of 1 amu

Solution

A homogeneous mixture where one substance called the solute is fully dissolved into another substance called the solvent. For example, a solution is formed when salt dissolves into water to make the solution salt water.

Homogeneous Mixture

having the same structure, nature, or texture throughout; uniform. one that's mixed or blended together so well that all of the ingredients will not separate out, even over time.

Heterogeneous mixture

a combination of two or more materials that are not blended evenly, making it easy to see the different parts.

family in the periodic table

a vertical column of elements (also known as a group) that shares similar chemical behavior, physical properties, and the same number of valence electrons. There are 18 numbered columns (groups) in the periodic table, where elements within a family exhibit similar reactivity and bonding patterns.

period on the periodic table

a horizontal row of elements, with 7 distinct periods in the modern table. Elements within the same period share the same highest electron shell number (energy level) for their valence electrons. As you move across a period from left to right, atomic number increases, properties change from metallic to nonmetallic, and atomic radius generally decreases.

Atomic number

total number of protons in an atoms nucleus

Atomic weight

number of protons plus neutrons in the nucleus usually expressed in amu’s

Element Symbol

Single upper case letter or uppercase and lowercase letter representing a specific element on the periodic table of elements (H) (Na)

Element Card

A card that provides essential information about an element, including its name, atomic number, symbol, and atomic weight. on the periodic table of elements