Scientists of the Past
The Periodic Table
The Atom
The Electron Cloud
100
This scientist gave the name to the smallest piece of matter, the atom.
Who is Democritus?
100
These are found to the left of the zigzag line on the periodic table.
What are metals?
100
These are positively charged and found in the nucleus of an atom. The number of these is the same as the atomic number.
What is a proton?
100
The first energy level holds this many electrons?
What is the number 2?
200
This scientist discovered the electron
Who is J.J. Thomson?
200
These are found to the right of the zigzag line on the periodic table.
What are non-metals?
200
These are negitavely charged and found outside the nucleus of an atom. They are equal to the number of protons.
What are electrons?
200
The second energy level holds this many electrons?
What is the number 8?
300
This scientist stated that the electrons were scattered outside the nucleus of the atom.
Who is Ernest Rutherford?
300
These are metal or metal-like elements found on both sides of the zigzag line.
What are metalloids?
300
These are nutrual and found in the nucleus of an atom. To find the number of these you must subtract the atomic number from the atomic weight.
What are neutrons?
300
The third energy level holds this many electrons?
What is the number 18?
400
This scientist developed the first periodic table of elements.
Who is Dmitri Mendeleev?
400
This is the vertical column of elements on the periodic table. They have similar chemical properties.
What is a group?
400
This is the space where electrons are likely to be found.
What is the electron cloud?
400
The fourth energy level holds this many electrons?
What is the number 32?
500
This scientist discovered that electrons move or orbit around the nucleus.
Who is Niels Bohr?
500
These are the horizontal rows of elements on the periodic table. They do not have similar properties.
What are periods?
500
This is a small dense area in the center of an atom.
What is a nucleus?
500
This must be done before going on to the next energy level.
What is completely filling the energy level?
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