subatomic particles that has a positive charge
proton
This group will never combine with any other element naturally.
noble gases / group 18
The period number tells you…
Number of energy levels
The number of protons and neutrons is represented by the…
mass number
charge of a neutron
the most reactive metals
alkali metals
These elements have both metallic and nonmetallic characteristics
metalloids
Isotopes are atoms of the same element with different numbers of what?
neutrons
Name the force that holds the nucleus together.
strong nuclear force
How many electrons can be held in the first energy level?
2
The most reactive nonmetals.
Halogens
Which number can be used to determine the identity of an element?
Atomic number
What noble gas does not have 8 valence electrons?
Helium
Describe the repulsive forces in the electron cloud.
Repulsive force between (–) electrons
This is where the electrons are located in an atom.
electron cloud / energy level
All elements in this group have 2 valence electrons.
Alkaline earth metals
How many protons and neutrons does a typical hydrogen (H) atom have?
1 protons & 0 neutron
Draw a Bohr Model for the most common isotope of Sulfur.
Describe the repulsive forces in the nucleus.
Repulsive force between (+) protons
This is where the mass of the atom is located/concentrated
nucleus
This element is the only one in its group that belongs with the group # (due to having the same # of valence e-) but not with the group name (because it is a different classification)
Hydrogen (H)
This element has 4 energy levels and is one of the rare earth metals.
Scandium
Describe the attractive forces that exist in an atom.
Attractive force between the (+) nucleus and (–) electron cloud