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12 Cards in this Set

  • Front
  • Back
how do you find valence electrons?
amount of electrons in last energy level
how do you find the amount of protrons?
atomic number
how do you find amount of electrons?
amount of protrons
how do you find amount of neutrons?
atomic mass- atomic number
what is an isotope?
atoms that have the same protrons but different neutrons
what is a quark?
Quarks are believed to be one of the basic building blocks of matter. Quarks were first discovered in experiments done at the Stanford Linear Accelerator Center in the late 1960's and early 1970's.
What is an atom and what is it made of?
Atoms are the basic building blocks of ordinary matter. Atoms can join together to form molecules, which in turn form most of the objects around you.

Atoms are composed of particles called protons, electrons and neutrons.
What is an element? How many elements are there?
An element is a substance that is made entirely from one type of atom. 117
Why are valence electrons impt and what are they?
In chemistry, valence electrons are the electrons contained in the outermost, or valence, electron shell of an atom. Valence electrons are important in determining how an element reacts chemically with other elements: The fewer valence electrons an atom holds, the less stable it becomes and the more likely it is to react.
how are periods arranged? (columns, rows)
how are groups arranged? (columns, rows)
who created periodic table?
Dmitri Mendeelv