atomic structure
definition of a atom
the fundamental building block of all matter
what is the periodic table
a list of all known elements
when do ionic bonds form
when atoms share electrons
what are the 2 main categories of elements that atoms can be sorted into on the periodic table
metallic and non metallic elements
define a mixture
made up of two or more different substances which are mixed but are not combined chemically
what does the atomic number represent
number of protons
what are the vertical columns on a periodic table called
groups
if an atom gains electrons to fill the outer shell what has it become
a negatively charged ion
list 3 properties of ionic compounds
high melting point, high boiling point, brittleness
define a element
a substance made up of only one type of atom
what does atomic mass represent
number of protons + number of neutrons
what are the rows on a periodic table called
periods
Ionic compounds are good conductors of electricity when they are:
dissolved in water
what are 3 properties of metallic elements
malleable, ductile, good conductors
define a molecule
a cluster (two or more) of atoms that makes up an element or a compound
what are the maximum number of electrons that can fit in the first 3 shells of an atom
2,8,8
how many elements are there on the periodic table in total
118
The force of attraction that holds together positive and negative ions is a:
ionic bond
what are 3 properties of non metallic elements
insulators, poor conductors, brittle
define a compound
made up of two or more different types of atom chemically joined
how do you find the number of neutrons in a atom
atomic mass - atomic number = number of neutrons
how many periods are there on the periodic table
7
what 6 atoms cant be ions
radon, helium, krypton, xenon, neon, argon (noble gasses)
what makes the 6 noble gasses different from the other elements
they have full outer shells
define a pure substance
a material that is only composed of one type of particle