Groups
vertical columns on the Periodic Table
Periods
Horizontal rows on the Periodic Table
Valence electron
electrons on the outer most electron shells
electrons
Negatively charged particles in an atom. Located outside of the nucleus
protons
positively charged particles in an atom. Located inside the nucleus
neutrons
particle located inside the nucleus with a neutral charge
Nobel Gasses
group 18 on PTE. Inert (will not react with other elements). Odorless gasses.
Halogens
group 17 on the PTE.
atomic number
number of protons in an atom (also tells you how many electrons are in an atom)
atomic mass
number of protons and neutrons in the nucleus of an atom
20
How many electrons are found in the element Calcium?
20
How many protons are found in the element Calcium?
(9.0122 - 4) = 5
How many neutrons are found in the element Beryllium?
4.0026
What is the atomic mass of Helium?
2
What is the atomic number of Helium?
H, He
Name 1 element in period 1.
Atomic mass - Atomic number
How do you find the number of neutrons in an atom?
Metals
Elements that are good conductors of electric current and heat.
Metalloids
Elements that have properties of both metals and nonmetals.
Nonmetals
Elements that are poor conductors of heat and electric current
Metals
Ductile, solid at room temperature, Shiny, malleable, high density
Nonmetals
dull, brittle, low density, less reactive, gas at room temperature
Group number (number at top of PTE)
tells you the number of valence electrons in an atom of an element
Period number (number down the side of PTE)
tells you the number of shells or energy levels in an atom of an element
increasing reactivity
from top to bottom of PTE and right to left of PTE
Group
all elements in a _______________ share similar chemical properties