Protons Neutrons and Electrons
What charge does a proton have?
Positive charge
What is an isotope?
Atoms with the same number of protons and a different number of neutrons
What infi is inside each square on the periodic table?
Atomic number, name, symbol, and atomic mass
What did Dalton do?
smooth solid hard spheres. all atoms of an element are the same and different from at5oms from other elements.
What are the physical properties of metals?
Malleable, ductile, conductive, and shiny
Wha is the mass or a proton (or a neutron)?
1 amu
what causes one element to change into another element
An unstable isotope
The three main categories for the elements of the periodic table?
metals, nonmetals, and metalites
What did Thomson do?
Discovered electrons with negative charges and assumed there were positives all around the negative charges (chocolate chip muffin or plum pudding idea)
What is created when a metal combines with another element?
Alloy
What charge does an electron have?
Negative charge
What makes an isotope unstable?
Different numbers of protons from neutrons
Left side = more reactive, it decreases in reactivity as you move to the right side of the table.
What did rutherford do?
He was a student of Thomson, who made the gold foil experiment, and discovered the nucleus with positive charges in the middle rather than mixed up like Thomson suggested.
What are the properties of a non-metal?
Dull, brittle, not conductive, lower density than metals
What charge does an atom have?
Neutral - protons and electrons cancel each other out.
What is an alpha particle?
Two protons and two neutrons that break away from the nucleus
Who organized the elements into a table, what is it called, and in what order?
Mendeleev organized elements into the periodic table and by order of atomic mass first, then Moseley reorganized it by atomic number.
What did Bohr do?
Was a student of Thomson and Rutherford who discovered that electrons move in a specific orbit.
What is a metaloid?
Has some properties of metal and some properties of a nonmetal.
What is the mass of an electron?
1/1837 amu (approximately 2000 electrons equal to 1 proton or 1 neutron)
What is a beta particle?
One less neutron and one more proton.
How many elements are on the periodic table?
118
What did Chadwick do?
Discovered neutron and electron clouds rather than orbits.
What is on the zigzag or staircase of the periodic table?
Metaloids