Atomic Structure – stuff you really need to know

inside an atom

a Carbon atom

Key things to take note of.

1. Position of protons, neutrons and electrons. 2. The number of protons, neutrons and electrons. 3. For an atom, the number of protons are equal to the number of electrons. (key point!!)

Key Terms you need to know when studying about the atom!

      • Sub-atomic particles: particles you find INSIDE the atom -?Protons, Electrons and Neutrons.
      • Nucleus:?Location of the protons and neutrons in an atom.
      • Nucleon:?Protons and neutrons collectively
      • Atomic/proton number: ?Number of protons in an atom. Element specific: different elements have different proton numbers. Also equal to the number of electrons in an atom.
      • Isotopes:??Atoms of the same element with the same number of protons but different number of neutrons. Popular example Chlorine -35 and Chlorine-37. Both have 17 protons BUT chlorine-35 has 18 neutrons and chlorine-37 has 20 neutrons.
      • Electron Shells:?Regions around the nucleus where electrons can be found.
      • Valence Shell: Outermost electron shell
      • Valence electrons: electrons found in the valence shell. Chemical properties of an element are dependent on this number. Determines the Group (Periodic Table) an element is located in.

One of the more popular questions on this chapter can be found below!

Popular Question 1.? The table shows the atomic structure of six particles, represented by the letters L to Q. The particles are atoms or ions. The letters are not the symbols of the elements.

Use the letters L to Q to answer the following questions.

      1. Which 2 particles are ions? (recall – different number of protons and electrons!)
      2. Which particle is an atom of a noble gas? (recall – stable electronic configuration!)
      3. Which 2 particles are an ion and atom of the same element? (recall – same element: same no. of protons; atom: same no. of protons and electrons; ion: diff. no. of protons and electrons)
      4. Which 2 particles are isotopes of the same element? (recall – isotopes: same no. of protons, different no. of neutrons)

This should be pretty simple once you understand the key terms and concepts!