Periodic Table 1
The electrons in the outer energy level
What are valence electrons?
An atom with a negative charge
What is an electron?
The atomic number tells you
What is the number of protons (and electrons) an atom of an element has?
An atom with a positive charge.
What is a proton?
A subatomic particle with no charge
What is a neutron?
The location of protons and neutrons.
What is inside the nucleus?
An atom with a completely full outer most (valence) energy level is this.
What is nonreactive also known as the Noble Gases
heavier versions of the same element; different number of neutrons/same number of protons
What are isotopes?
What is most reactive nonmetals?
The elements in groups 3-12 are known as
What are the transition metals?
Atomic mass - Atomic number
What is the formula for finding the neutrons of an atom?
8
What is the maximum number of electrons the 2nd orbital, or energy shell, can hold?
Rows on the periodic table; energy levels/shells
What are periods? What do they tell us?
Columns on a periodic table
What are groups?
Elements in the same group share this.
What are same number of valence electrons or similar chemical properties
atomic mass and chemical properties
What Mendeleev organized the periodic table according?
The alkali metals = 1 valence electron
The alkaline earth metals= 2 valence electrons
Name the first two chemical families
how many valence electrons?
The majority of the elements on the periodic table are this.
What are metals?
Chemical rule of thumb that state atoms have the tendency to prefer to have eight electrons in the valence shell.
What is the octet rule?
The three classes of elements on the periodic table
What are metals, metalloids, and nonmetals?
Mass number is the combination of neutrons and protons; the average atomic mass is the weighted average of isotopes
what is the difference between the decimal mass and the whole number mass of an element?
These increase by one as you move across the periodic table
What is atomic number/protons?
Elements in group 1 have only 1 valence electron and are considered ______________ reactive
What are elements that are considered extremely reactive?
Uranium with a mass of 235 and Uranium with a mass of 238 would be considered to be
What are isotopes?
Helium has ____ valence electrons
What is 2?