top number of the number on an element in the periodic table
mass number protons + neutrons
bottom number of the number on an element in the periodic table
atomic number tells number of protons
isotope
An isotope is a version of an element with the same number of protons but a different number of neutrons.
ion
atom/molecule that gains or loses electrons
what is electonic configuration
Electronic configuration is the arrangement of electrons in the orbitals of an atom
compound
2 or more substances chemically joined together
mixture
2 or more substances mixed together ( not chemically bonded)
seperating methods
-evaporation and crystallisation
-distillation
-filtration
-chromatography
-
covalent bond
sharing of electrons between 2 atoms
ionic bonding
Ionic bonding is the electrostatic attraction between positively charged ions (cations) and negatively charged ions (anions), formed when electrons are transferred from a metal to a non-metal.
what are delocalized electrons
electrons in a molecule that are not associated with a single atom or covalent bond
what are valence electrons
metallic bonds
metals lose electrons, electrons delocalise to move freely between positive metal ions
how Mendeleev arranged elements in the PT
Mendeleev organized the periodic table by increasing atomic mass and grouping elements with similar properties t
finding number of neutrons
mass number -atomic number
Explain how cations and anions are formed
Cations and anions are formed when atoms gain or lose electrons to achieve a stable electron configuration
cation
positively charged ion
anion
negatively charged ion
