chemistry - assessment

Democritus model

the simple model

John dalton model

dalton model

jj thomson model

plumb pudding model

ernest Rutherford model 

the planetary model 

niels bohr model

bohrs model

erwin Schrödinger model

the quantum model

atomic number

number of protons in atoms nucleus

atomic mass

the average mass of an element

valency

combining capacity of an atom

difference between a cation and an anion

cations have more protons than electrons while anions have more electrons than protons

trends that govern atomic radii on the periodic table

increase as you move down, decrease as you move left to right

difference between covalent radii and ionic radii

covalent are equal to one another while ionic are greater for anions and lesser for cations

what is the difference between an orbit and an orbital

orbit is the idea that electrons travel in fixed circular paths around the nucleus. orbital is the idea of a three dimensional region where there is high probability of finding an electron. orbitals have different shape and are are based on quantum mechanics not paths