Science - Chemistry: Atomic Structure Flashcards
element
a substance made up of only 1 type of atom. each has a symbol
atom
small particles that make up elements
atomic number
the number of protons in an element
atomic mass
the number of protons and neutrons in an element (decimal number because of all the isotopes)
protons
positively charged particles in the nucleus of an atom
neutrons
neutral particles in the nucleus of an atom
electrons
negatively charged particles that orbit an atom
nucleus
made up of protons and neutrons. most of the mass of the atom is in the nucleus.
neutral atom
elements on the periodic table. an equal mount of protons and electrons.
isotope
atoms of the same element that have a different number of neutrons (e.g. carbon-13)
mass of atom=
protons + neutrons
charge of atom=
protons : electrons
stability of atom=
neutrons : protons
types of elements
metals, non-metals and metalloids
periodic table
118 known elements. made up of groups and periods
ion
an atom with a different number of protons to electrons. ions have a charge which can be negative or positive.
cation
a positively charged ion. made when an atom loses electrons. (e.g. Mg2+)
anion
a negatively charged ion. made when an atom gains electrons. (e.g. N3-)
single atom
one atom of one element
molecule
multiple atoms of one or more type of element
crystal lattice
a grid like atomic structure with one or more elements
metals
- lustrous
- malleable
- ductile
- good conductors of electricity
metalloids
- brittle
- lustrous
- semi-conductors of electricity
non-metals
- brittle
- dull
- poor conductors of electricity
group
shown along the x-axis of the periodic table. tells how many valence electrons there are in an element
period
shown along the y-axis of the periodic table. tells how many shells there are in an element
