Atomic Structure Notes

Review

What is an atom?

Atomic Symbol

-The shorthand abbreviation that is used to identify an ______(element name)

-Atomic symbols have

  • A ______letter at the ______of the symbol (all symbols have this)
  • Some have a ______case letter after the capital letter
  • Be careful! The letters of the atomic symbol do not always match the name of the element
  • Examples:

Hydrogen______

Helium______

Magnesium______

Potassium______

Iron______

Sodium______

  • Label the element name and atomic symbol on the diagram above

Nucleus (discovered by ______ in 1911)

-The ______ of the atom

-Contains a majority of the ______ of the atom (99.9%), but a small portion of the ______

-Relative size of the nucleus:

-The nucleus contains:

  • Protons
  • Have a ______ charge
  • Have a mass of ______grams or _____ atomic mass units (amu)
  • The number of ______determines the type of ______ that you have!! (If you change the number of protons, you change the element!)
  • We call this the ______
  • Label the atomic number on the diagram above

Complete the table below. Use the Periodic Table on p. 518 to help you.

Element / Atomic Symbol / Atomic Number / # of Protons
29
Br
82
  • Neutrons(Discovered by ______ in 1932)
  • Are ______, which means they have no ______
  • Have a mass of ______grams or _____ atomic mass units (amu)
  • To determine the number of neutrons in an atom, you need to know the atom’s mass number
  • ______: the ______of the number of ______and the number of ______in the nucleus of an atom
  • # of Neutrons = ______
  • If you are given the mass number and the number of neutrons, how can you figure out the number of protons?
  • Protons and Neutrons can both be broken down even farther into ______. More info on pg. 508

Electrons (Discovered by ______in 1904)

-Have a ______ charge

-Have a very small mass (approximately 9.1093 x 10-28 grams or ______amu)

-In a ______ atom, the total number of electrons______the number of protons

-Can be found in ______surrounding the nucleus (Developed in 1926)

  • Electrons are so small and move so quickly that it is impossible to determine their exact locationhowever we can predict it based on probability
  • The electron cloud is approximately 100,000 times larger than the nucleus
  • Each electron cloud has a different amount of ______
  • The electron clouds closest to the nucleus have the ______ amount of energy, and the electron clouds furthest from the nucleus have the ______ energy
  • Electrons fill the energy levels from the ______levels to the ______levels
  • Each level can hold a specific number of electrons

Drawing Atomic Structure

Draw a diagram of a neutral atom for the element that contains 2 protons and has a mass number of 4.

Element name: ______

Protons: ______

Electrons: ______

Neutrons: ______

Draw a diagram of a neutral atom for the element that contains 12 protons and has a mass number of 24.

Element name: ______

Protons: ______

Electrons: ______

Neutrons: ______

Draw a diagram of a neutral atom for the element that contains 9 electrons and has a mass number of 19.

Element name: ______

Protons: ______

Electrons: ______

Neutrons: ______

Isotopes
  • ______ofthe same ______ that contain the same number of protons, but a different number of ______
  • Because isotopes have a different number of neutrons, they also have different ______.
  • Most elements have more than one isotope, and therefore have an average ______.
  • The average atomic mass is the ______mass of an element’s various isotopes (takes into consideration which isotopes are more ______than others).
  • The average atomic mass can be found on the Periodic Table. Label this on the diagram on the first page.
  • Isotopes can be symbolized in a few ways:

1)Atomic symbol, mass number, and atomic number

2) Atomic name or symbol with a hyphen and ______.