Introduction to Atomic Particles

Introduction to Atomic Particles How will I know if I am successful? I can name and describe three types of atomic particles Charge Location Mass I can find the atomic number and mass number, and can explain what they represent I can calculate the number of neutrons in an atom

What are atoms? Subatomic particles An atom a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons The atom is made up of three different types of particles called . Subatomic particles

Protons positively nucleus Mass of 1 amu charged Located in the Each proton has a (atomic mass unit) nucleus Mass of 1 amu

Neutrons neutral nucleus Mass of 1 amu particles Located in the Each neutron has a neutral nucleus Mass of 1 amu

Electrons negatively charged Move rapidly in space (in orbits) Have almost Around the nucleus No mass

Model of the Atom The physicist Nils Bohr developed a model of the atom that looked like the picture below. Part of Atom Count protons neutrons electrons nucleus total total charge   11 12 11 23

Parts of the Atom Part of Atom Overall Charge Atomic Weight (amu) Description (where found?) nucleus   0 (neutral) depends on atom proton neutron electron Centre of the Atom +1 (positive) 1 In Nucleus Part of the Nucleus 0 (neutral) 1 In Nucleus -1 (negative) Almost 0 Around Nucleus

Standard Atomic Notation is an internationally recognized system that allows anyone to communicate information about the atom

Note- In the periodic table, notation looks like this:

protons protons neutrons Atomic Number - Number of (also equal to the number of electrons in a neutral atom) - Determines the identity of the atom Mass Number - the sum of the and in an atom - mass number = atomic number + number of neutrons protons protons neutrons

Calculating Neutrons Number of neutrons = E.g. 2 2 2 Mass Number (protons + neutrons) – Atomic Number (protons) E.g. Protons: Neutrons: Electrons: 2 2 2

Time to practice on your own!