mid year science review
Chemistry , earth history , infectious disease
Chemistry Unit
Periodic Table
The periodic table is organized by increasing atomic numbers . Elements are grouped together by groups / families .
Atomic Mass and Atomic Number
The number of protons in the nucleus of an atom determines an elements atomic number .
Protons, Neutrons, and Electrons
Atoms are the basic units of matter and the defining structure of elements. Atoms are made up of three particles: protons, neutrons and electrons. Protons and neutrons are heavier than electrons and reside in the center of the atom, which is called the nucleus.
Groups and Periods
Groups are the the columns on the periodic table that goes up and down / vertical .
Periods are horizontal rows on the periodic table .
Law of conversation of matter
The law of conservation of mass states that matter cannot be created or destroyed it can only be transferred from state to state .
Elements , compounds , mixtures
Compounds - two or more atoms combined Mixture -