Chemistry Unit 1 Flashcards
Define: Matter
anything that takes up space and mass
Define:Mixed substance or Mixture
made up of components not found on the periodic table i.e. a mixture
Define: Heterogeneous Micture
a mix f substances that have 2 or more phases (appears as more than one thing)
Define: Homogeneous Mixture
a mix of substances that have one phase and therefore it looks uniorm
Define: Pure Substance
made up of only type of atom found on the periodic table. It contains 1 phase and is homogeneous
Define: Element
only one particle that cannot be broken down any further and is straight off the periodic table
Define: Compound Molecule
contains two or more elements that move as a single unit
Define: Atom
the smallest particle of matter
Define:Atomic Theory
a theory describing the structure, behavior and other properties of an atom and it components/parts
Define: Proton
a subatomic particle that has a charge of +1, a mass of 1 amu and is found in the nucleus
Define:Neutron
a subatomic particle that has a neutral charge, has a mass of 1 amu and is found in the nucleus
Define: Electron
a subatomic particle that has a charge of -1, has a mass of approx. 0 amu and is found orbitting the nucleus in shells
Define:Nucleus
the very dense center of an atom which contains the protons and the neutrons of the atom.
Define:Shells
The rings around the nucleus where electrons orbit the nucleus and can be exchanged or shared among atoms
Define:Bohr-Rutherford Diagram
a diagram created to show the atom with its nucleus and all its electrons on their shells
Define: Valence Electrons
the electrons on the outermost shell. They are the extra or lacking atoms sitting on the outer shell.
Define: Valence Shell
the outermost shell in an atom containing electrons
Define: Periodic Table
a way of organizing all the elements in a realistic way where they can be organized by re-activity, state and mass
Define: Period
the horizontal rows on a periodic table
Define: Group / Family
the vertical columns in the periodic table. Elements of the same group have the same number of valence electrons
Define:Metal
conduct electricity well. These include all elements to the left of the “staircase” excluding hydrogen
Define: Non-metal
do not conduct electricity well and act as insulators. These include all elements to the right of the staircase plus hydrogen
Define: Metalloid/Semi-Metal
have properties of both metals and non-metals. They are the elements that make up the staircase
Define: Alkali Metal
are highly reactive because the atom is unstable. They have 1 valence electron so they lose one electron and have an overall charge of +1
Define: Alkaline Earth Metals
are reactive because they have 2 valence electrons so they lose 2 electrons to have an overall charge of +2
Define: Halogen
highly reactive non-metals because they have 7 valence electrons therefore they only need to gain one electron so they will gain 1 electron to have a charge of -1
Define: Noble Gas
gases that are very unreactive because they already have a full shell therefore cannot gain or lose electrons
Define: Atomic Number
is the number of protons or electrons