1. explain three ways how the periodic table is organized and how elements are grouped? ?
2.
3.
4.
2. what 3 characteristics does the periodic table list for each element?
1.
2.
3.
4. what is the atomic number?
5. what do we use the atomic number to find?
6. what is the atomic mass?
7. how do we find the amount of neutrons in an element?

Periodic table is organized by their valence electrons, atomic number and their atomic mass ( and also their reactivity/ groups and families). Periodic table lists their elemental symbol, atomic mass and their name. Atomic number is the number of protons and (electrons). Atomic number help us find their location on the periodic table and also their protons and electrons. The atomic mass is the mass (weight) of the specific element (per atom). The atomic number subtracted from the atomic mass is the number of neutrons. 

Three reasons of the deaths of native americans: new illnesses that their immune systems couldn't cope with. genocides so the settlers could have the good land.starvation from lack of rations and poor infertile land on resevations