orbitals and atomic structure

orbitals and atomic structure

1. Atomic orbitals are regions of space around the nucleus of an atom where an electron is likely to be found. Atomic orbitals allow atoms to make covalent bonds. The most commonly filled orbitals are s, p, d.

   • s orbitals are a spherical shape and p orbitals are a dumbbell shape .

2. The structure of an atom. The nucleus contains positive protons and neutral neutrons. Surrounding the nucleus are energy shells containing negative electrons. You should also know that protons and neutrons both have a relative mass of 1 and that the relative mass of an electron is almost 0.

   • The protons and the neutrons are found in the nucleus at the centre of an atom. The electrons are in shells or energy levels surrounding the nucleus. Each shell can hold electrons up to a maximum number. When the first shell is full, electrons then go into the second shell and so on.

3. Electrons within each shell will not have the same amount of energy and so the energy levels or shells are broken down into subshells called orbitals. These are called s, p, d and f orbitals. The orbitals have different energy states.

4. The Aufbau principle states that electrons fill the orbital with the lowest available energy state in relation to the proximity to the nucleus before filling orbitals with higher energy states. This gives the most stable electron configuration possible

5. Electrons have the same charge and so repel each other, so if there is more than one orbital in an energy level (sub-shell) they will fill them singly until all the orbitals in that sub-shell have an electron in them and then they will pair up.