Chem Exam #1

Law of Definite Proportions

All samples of a given compound of their source have the same proportions as their constituent elements

Law of Multiple Proportions

When 2 elements form 2 different compounds, the masses of Element B that combine with 1g of Element A can be expressedas a ratio of small whole numbers

Rutherford’s Nuclear Theory

Most of the atom’s mass and all of its positive charge are contained in the nucleus. Even amount of electrons + protons

Atomic Radius

• Distance of outermost shell from nucleus, size of atom

• Decreases across PT → protons pull e- closer to nucleus

• Increases down PT → more shells are added

Ionization Energy

• Energy required to remove e- from atom

• Increases across PT → makes it harder to remove e- because valence electrons are attracted to nucleus

• Decreases down PT → E- are further from nucleus

Electron Affinity

• Energy change when an e- is added to an atom

• Increases going across PT -→ atom gets closer to its affinity

• Decreases going down → atomic sizes increase and incoming e- enter further from nuclues