CH 11 & 12 Flashcards
the smallest particle an element can be broken down into and still maintain its identity.
Atom
What atom means in Greek
“Not able to be divided or indivisible”
negative charge, amu 1/1800 least mass almost 0
Electrons
positive charge, amu 1
Protons
neutral charge, amu 1
Neutrons
protons + neutrons
Mass number
number of protons in the nucleus
Atomic number
describes the mass of an atom in SI units
Atomic mass unit
mass of an atom in A.M.U. (Atomic Mass Units)
Atomic mass
All matter is made up of…?
Atoms
What is in the center of an atom?
The nucleus
always have the same number of protons, but different neutrons.
Isotopes
keeps the protons together in the nucleus.
Strong force
holds electrons in place around the nucleus.
Electromagnetic force
pulls objects toward one another.
Gravitational force
Many elements have how many isotopes?
2 or more
Most of the elements on the periodic table are…?
Metals
The horizontal rows on the periodic table are called…?
Periods
The vertical columns on the periodic table are called…?
Groups or families
The color of the chemical symbol tells…?
the physical state of an element at room temperature
As you move across each period the chemical and physical properties of elements change from…?
most metallic to least metallic
Mendeleev arranged his periodic table by…?
increasing atomic mass
Mendeleev found that the properties of known elements did what?
repeated a pattern every 7 elements
Each square on the periodic table includes
an element’s name, chemical symbol, atomic number and atomic mass.
