atoms and periodic table unit test
How many elements are on the periodic table?
118 elements
how many electrons can the first shell of an atom hold?
2 electrons
What do the periods in the periodic table tell you?
How many shells an atom has
what part of the periodic table are there seven of?
Periods (horizontal rows)
Heisenberg was the first to prove which theory?
Quantum theory
Who was Dmitri Mendeleev?
Scientist who better organized the periodic table and found a way to predict new elements
how do you get the number of neutrons in an element?
Subtract atomic number from atomic mass
the atomic theory is based on the ideas of...
all scientists who have worked on it
the periodic table lists...
all the elements that make up the physical universe
what is the smallest part of all matter?
an atom
what do the numbers in the top of the boxes of each element stand for?
atomic number
what do the 1-2 letters in the boxes on the periodic table represent?
chemical symbol
What did John Dalton do?
developed the atomic theory
What did Rutherford do?
discovered that most of the atom is empty space, but it has a dense central nucleus.
What did JJ Thomson do?
discovered the electron
what is the abbreviation for electrons?
e-
JJ Thomson discovered which subatomic particles?
electrons
What did Democritus do?
first to use the term "atomos" for smallest piece of matter
How are the elements in the periodic table arranged?
from lightest to heaviest
what is the bond called between different types of atoms?
heteroatomic bonds
what is a bond called between the same type of atoms
homo-atomic bonds
What did Neils Bohr do?
made the planetary model
What kind of charge do electrons have?
negative charge
What kind of charge does a neutron have?
no charge or neutral charge
what kind of charge do protons give off?
positive charge
what are the three subatomic particles that make up an atom?
proton, electron, and nutron
What are the properties of metals?
shiny, malleable, good conductors of heat and electricity
what make the valence shell more reactive?
space for more electrons
how do you find the number of protons or electrons
the atomic number is the number of both the electrons and protons meaning: electrons=protons
Rutherford discovered what?
the nucleus
why are elements arranged in groups
they contain properties that are similar
how many atoms make up a molecule
two or more atoms
how many electrons can the second and third shells hold?
up to 8 electrons
what are the electrons on the valence shell called
valence electrons
what is the outside shell of an atom called
valence shell
the question that lead to the work on the atomic structure was:
why do atoms behave the way they do?
