Electrons that are not valence electrons are called this.
What is "core electrons?"
100
This is why Dalton's atomic theory has been called "The first modern atomic theory."
What is: His is the first atomic theory based entirely on experimental evidence (his own experiments and the previous work of many other scientists).
100
This was the discovery for which Thomson won a Noble prize.
What is discovery of the electron, a tiny negatively charged particle within every atom.
100
All atoms have both negative and positive charges, but this situation must exist in order to call an atom "charged."
What is: unbalanced numbers of protons and electrons?
200
The elements called "halogens" form this group number.
What is Group 17?
200
This is the period number that includes the element, Uranium, atomic number 92.
What is Period 7?
200
This is what someone might draw in order to illustrate Dalton's model of the atom.
What is a simple sphere?
200
This is why Thomson conceived of the idea of positively charged "pudding" as part of his Plum Pudding atomic model.
What is: atoms are electrically neutral? (His negative electrons had to be balanced by equal positive charge for his model to be valid.)
200
In order to form an ANION, this must happen to an atom.
What is gaining one or more electrons?
300
These elements already have stable octets and do not need to react (group # and name of the group).
What is Group 18 and Noble Gases?
300
The elements in groups 3 - 12 are referred to as this.
What are transition metals?
300
These are two of the tenets that make up Dalton's atomic theory. (There are 4 possible tenets you can cite.)
variable......
300
If Thomson's model was correct, this would have happened when Rutherford tested it with alpha particles and gold foil.
What is: all alpha particles would have gone straight through the atoms in the gold foil and not been pushed in varying directions (deflected).
300
When barium becomes an ion, this change in its atomic structure happens.
What is losing 2 electrons?
400
The elements of this Group (give # and name of elements) have just 2 valence electrons.
What is Group 2, the Alkaline Earth Metals?
400
This is the entire group of elements that are found in nature as diatomic molecules, like hydrogen (H2), oxygen (O2), and nitrogen (N2).
What are the halogens: fluorine, chlorine, bromine, and iodine?
400
These are two tenets (not mentioned before) that make up Dalton's atomic theory.
Variable....
400
This is the model Rutherford described after analyzing results of his gold foil experiments.
What is: a nuclear atom that has a dense area of positive mass (nucleus) in the middle of empty space. Electrons move--possibly in orbits like planets, within the empty space.
400
Of atomic number, mass number, average atomic mass, and number of neutrons, this number or numbers are the ones that appear on the periodic table.
What are atomic number and average atomic mass?
500
In Group 13, elements do this in order to obtain a stable octet.
What is: lose 3 electrons and become 3+ ions.
500
Selenium, atomic number 34, needs this many electrons to fill up its valence shell (or attain a stable octet).
What are 2 electrons? (It has 6 valence electrons. It is in
Group 16).
500
These are the two concepts in Dalton's theory that are not true based on more recent knowledge of the atom.
What are: 1) Atoms are indivisible particles.
2) Atoms of a specific element are alike in all properties including mass.
500
This is how Thomson knew that there are negative particles inside every atom.
What are: Cathode ray tube experiments? (Include explanation of how Thomson showed the cathode ray had negative charge.
500
Zinc-95 is an isotope of zinc. These are the number of electrons in a neutral atom of Zinc-95, and the number of neutrons in a neutral atom of Zinc-95.