Elements and Atoms Flashcards
What are the most abundant elements on earth?
Oxygen, Silicon, Aluminum
What is Dalton’s atomic theory?
each element is made up of atoms
atoms cannot be created or destroyed
all atoms of each element are identical in every aspect
atoms of one element are different from atoms of any other element
atoms of one element may combine with atoms of another to form chemical compounds
What portion of the atomic theory is no longer valid?
each element is made up of atoms
atoms can’t be created or destroyed
all atoms of each element are identical in every aspect
Mass (amu) of an electron, proton, and neutron
0, 1, 1
Where are electrons, protons and neutrons located
electrons outside nucleus, protons and neutrons inside nucleus
Who discovered electrons and when?
Thomson 1897
Who discovered protons and when?
Rutherford 1919
Who discovered neutrons and when?
Chadwick 1932
Describe the experiment performed by Ernest Rutherford
Started in 1911, made a series of experiments on alpha particles that eventually led to the development of the nuclear model of the atom.
What were the results of Rutherford’s experiment?
every atom contains a small, dense nucleus
all positive charge and mass is contained in the nucleus
the nucleus is surrounded by large volume of empty space
the space outside the nucleus is thinly populated by electrons
Atomic mass number
sum of protons and neutrons and printed as decimal number
Atomic number
equal to number of protons and is a whole integer number
Isotopes
atoms of the same element with a different number of neutrons
How do you name an isotope?
by mass number
