This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Chemistry Atomic structure • Atoms have a simple structure o central nucleus: almost all of the mass proton: mass is one Dalton and charge is +1 neutron: mass is one and charge is 0 o Orbitals: large surrounding area, separate from the nucleus, electrons are here o electron: mass is very little, -1 charge o This is where the electron is most likely, we don't know the exact location, but it's probably there. We don't know how it's moving either o Orbitals can be found at varying distances Electrons and Orbitals • Electrons don't move in specific pathways. They don't actually orbit around the nucleus. This is why we can't predict exactly where they are • Orbital: the area around the nucleus where the electron is most likely found o each orbital can hold max 2 electrons • Orbitals have different energy levels. Orbitals with the same energy level are in the same shell. They are organized into shells. Shells describe the energy level of electrons. Electrons and orbitals Each of these is an orbital. (Don't need to know specific names) Energy Levels • Each electron has a certain amount of energy. It has to do with its distance from the nucleus. • The further from the nucleus, the more energy it has. The closer, the less energy. • Electrons in different orbitals can have the same energy level. This is because they have the same distance to the nucleus. • Electrons don't randomly fill the orbitals. The closest ones are filled first. The rest are filled in order from nearest to furthest. • Number and arrangement of electrons in orbitals determines chemical reactivity. Whether they'll combine and form bonds or not, …. • Figure 2.4b and 2.5 – Test questions can be on the figure! o K is closest and has the lowest energy level, can gain energy can go up to L. If it moves from L to K, it releases energy. Chemical reactivity • Valence electrons are electrons in the outermost energy level, in the outermost orbitals. • Interactions of valence electrons determine chemical reactivity • Octet rule: energy shells usually hold max 8 electrons, atoms tend to fill up their valence shell. When the octet rule is satisfied, the atom is stable. It will do anything to satisfy the octet rule. Redox reactions • Transfer of electrons from one atom to another. This could fill a valence shell....
View Full Document
This note was uploaded on 03/25/2010 for the course BIO 11000 taught by Professor Friedman during the Spring '10 term at Purdue.
- Spring '10