Parts of an Atom indiana.edu Ms. Mandel Honors Physical Science
The Structure of Atoms
Learning Target I can differentiate between the parts of an atom.
What is an atom? The smallest unit of an element. The building blocks of all matter.
How small is an atom? An atom is so small that a penny contains about 2 x 1022 or 20,000,000,000,000,000,000,000 atoms!!!
What are the parts of the atom? Protons Neutrons Electrons
Parts of an Atom The protons and neutrons make up the center or nucleus.
Small, dense (packed tightly) Contains protons and neutrons The Nucleus The center of an atom Small, dense (packed tightly) Contains protons and neutrons most of the atom’s mass
Protons Located in the nucleus Positive charge (+) Mass of 1 atomic mass unit (amu) protons = positive
Have no charge - neutral Mass of 1 amu Neutrons Located in the nucleus Have no charge - neutral Mass of 1 amu neutrons = neutral
Electrons Found outside of the nucleus in electron clouds (think of rings around a target) Negatively charged (-) Mass of almost zero Number of electrons equals the numbers of protons to cancel out the charges (think of -1+1=0) electrons = negative
What holds an atom together? Electric force Positive protons are attracted to negative electrons The force holds the atom together
Learning Target Checkpoint Parts Charge Location Mass Proton Neutron Electron 1 amu Positive (+) Nucleus No charge Nucleus 1 amu Electron Cloud Negative (-) Almost zero
How many protons does C have? Atomic Number Atomic Number (Z) = # protons (p+) Each element has a UNIQUE # of protons How many protons does C have? 6
Mass Number Mass Number (A) = number of protons (p+) + number of neutrons (n°) What is the mass number of Nitrogen if it has 7 neutrons? 14 # neutrons = A - Z
? What is Z? 3 How many neutrons? 4 How many electrons? May also be written: Element name – mass number Ex. Lithium - 7 chemteam.info ieshermanosbilingual.blogspot.com What is Z? 3 How many neutrons? 4 How many electrons? ? chemteam.info
What element or elements is it? Mass Number = 1 Mass Number = 2 Mass Number = 3 eqseis.geosc.psu.edu What are these called? Isotopes