C1 Flashcards
(20 cards)
State the masses of the sub-atomic particles
Proton +1, neutron 1, electron almost 0
State the relative charges of the sub-atomic particles
Proton +1, neutron 0, electron -1
What did the gold foil experiment prove
That atoms have a small dense nucleus in the center with a positive charge
what is the atomic number of an atom
the number of protons in an atom
what is the mass number of an atom
the number of protons + number of neutrons in the atom
what did chadwick discover
existence of neutrons
what did bohr’s experiments show
that electrons are in specific shells (energy levels)
what are isotopes
atoms of the same element with the same number of protons but a different number of neutrons
what can the group number tell you about an atom of an element in that group
number of electrons in the outermost shell of the atom
what can the period number tell you about an atom of an element in that period
number of electron shells in the atom
who discovered the plum pudding model
J.J Thompson
Why did Mendeleev put some elements in groups
Because the had similar properties
who did the alpha scattering experiment
E. Rutherford
write the electronic structure of the element in group 4, period 3
2,8,4
Why did mendeleev leave gaps in his periodic table
For elements that had not been discovered. yet
what is a molecule
2 or more atoms covalently bonded together
what is an element
group of atoms or molecules where all the atoms are identical
what is a compound
2 or more different atoms chemically bonded together
what happens to the reactivity of the elements as you go down group 1
Increases
what happens to the reactivity of the elements in group 7 as you go down the group
Decreases
