Science test study guide Flashcards
Alkali metals
Soft, silvery coloured metals
Very reactive!!!
Alkali earth metals
Silvery-White Metals
Fairly reactive
Many are found in rocks in the earth’s crust
Period
Across a row (periodic table)
Group
Down a column (periodic table)
Transition metals
Most are good conductors of electricity
Malleable (easily bent/hammered into wires or sheets)
Metalloids
They share properties with both metals and nonmetals.
Si (Silicon) and Ge (Germanium) are very important “semiconductors.
Nonmetals
Brittle
Do not conduct electricity
Halogens
Most are poisonous
Fairly reactive – react with alkali metals (eg) Na+ and Cl-
Noble gases
Unreactive
Gases at room temperature
Lanthanides
Reactive and silvered colored metals
all have 3 electrons (except europium and ytterbium)
Actinides
They all are radioactive
they all have no stable isotopes
React with boiling water
tend to be soft (malleable and ductile)
Metallic character
Properties of a Metal –
Easy to shape (malleable); many are ductile (can be pulled into wires)
Conduct electricity and heat
Shiny
Isotope
Atoms of the same element having different masses due to varying numbers of neutrons.
Name them based on there mass number.
Ion
An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
Cation
A positively charged ion
metals tend to lose electrons
Anion
A negatively charged ion non metals tend to gain electrons
Semiconductor
Materials which have a conductivity between conductors (generally metals) and nonconductors or insulators (such as most ceramics). Semiconductors can be pure elements, such as silicon or germanium, or compounds such as gallium arsenide or cadmium selenide.
Electronegativity
Tendency of an atom to attract e-.
Properties of noble gases
They all conduct electricity, are odorless and colorless, and are used in many conditions when a stable element is needed to maintain a safe and constant environment. This chemical series contains helium, neon, argon, krypton, xenon, and radon.
Why the periodic table is important
It arranges all the known elements in an informative array.
Two types of covalent bonds
Polar and non polar
Characteristics of non polar bonds
The pull is shared equally by the atoms
Characteristics of polar bonds
The pull is shared unequally by the atoms
Ionization energy
The needed energy to remove outermost e-.