atoms
This is the number of protons AND neutrons in an atom's nucleus.
What is the mass number?
What is the trend for the reactivity of metals on the Periodic Table?
Reactivity increases as you go down and to the left. Francium is the most reactive metal.
The weighted average mass of all of an element's isotopes.
atomic weight
The ease and speed with which an element combines with other substances (and releases energy).
What is "reactivity".
His gold foil experiment showed that most of an atom's mass is located in the nucleus.
Ernest Rutherford
The two subatomic particles with the same mass.
What are neutrons and protons?
What is the least reactive family in the Periodic Table?
The Noble Gases. They are all nonmetals with full valence shells.
This happens to the atomic number of elements as you travel right and down on the periodic table.
What is increases.
These nonmetals have a full valence shell and are non-reactive or inert.
What are the noble gases?
J.J. Thompson discovered this subatomic particle.
What is the electron?
A group of two or more atoms held together by chemical bonds.
What is a molecule?
These elements include semiconductors.
What are the metalloids?
These elements are brittle, not malleable.
What are nonmetals?
This nonmetal is included with Group 1 elements, since it has 1 valence electron.
What is hydrogen?
He developed the planetary model of the atom.
Who was Neils Bohr?
If an atom has a balanced electrical charge, it has the same number of these 2 subatomic particles.
What are electrons (-) and protons (+).
He organized the first periodic table of the elements.
Who is Dimitri Mendeleev?
These elements in Group 3-12 of the periodic table are used to make jewelry and in construction.
What are the transition metals.
Metals are found on this side of the periodic table
What is the left?
He developed the current (modern) atomic cloud model.
Who was Erwin Schrodinger?
Two atoms with the same number of protons but a different number of neutrons.
What are isotopes?
Periods are set up in this direction on the periodic table.
What is horizontally?
Metalloids touch this feature on the periodic table.
What is "the staircase".
At room temperature, half of nonmetals are found in this state.
What is a gas?
He discovered the neutron.
James Chadwick