2ISOTOPESIsotopes are atoms that have the same number of protons, but have different numbers of neutrons.Having a different number of neutrons gives the atom a different mass.
3Isotopes of the same element are similar to one another in many ways. Some elements have isotopes whose properties differ in important ways.
4PROPERTIES OF ISOTOPES Some isotopes of an element have special properties because they are unstable.This type has a nucleus that will change over time.These are radioactive because they will fall apart over time.Most isotopes share mostof the same properties.
5The Difference Between Isotopes You can identify an isotope by its mass number.The mass number is the number of protons and neutrons added together.Compare these three carbon atoms to see how we determine the mass number for each.
6NAMING ISOTOPESTo identify a specific isotope of an element, write the name of the element followed by a hyphen and the mass number.Example:Hydrogen – 2Hydrogen - 3
7Isotopes and Atomic Mass Most elements contain a mixture of two or more isotopes with different #’s of neutrons.The atomic mass of an element is the average of the masses of all the naturally occurring isotopes of that element.This number is found on the element card on the periodic table.6C12.01ATOMIC MASS
8Forces in AtomsThere are four basic forces acting between the particles in an atom that hold them together.These forces work together to give an atom its structure and properties.
9Gravitational ForceGravitational force pulls objects towards one another.The masses of the particles in atoms are so small, this force within atoms is very small.
10Electromagnetic Force Protons and electrons are attracted to each other because of this force.
11STRONG FORCEProtons push away from each other because they have the same charge.The protons would fly apart if it wasn’t for strong force.
12WEAK FORCEThe weak force is an important force in radioactive atoms.In certain atoms, a neutron can change into a proton and an electron.The weak force plays a big part in this change.+NEUTRAL-
13IONSAn ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons,