1. The Periodic Table of Elements The Periodic table of elements is a way of presenting all 118 elements to show their similarities and their differences. The periodic table of elements is arranged in increasing order of number of protons.

2. Atomic Number The number of protons in an atom. The elements in the periodic table are listed according to the atomic number. The number of protons is equal to the number of electrons in an atom. 6 C Carbon 12.0115

3. Atomic Symbol One two or three letters used to represent the atom of an element. 6 C Carbon 12.0115

4. Atomic Mass The weight of an atom. The atomic mass is the sum of the protons and neutrons in the nucleus. 6 C Carbon 12.0115 Take the challenge on your sheet.

5. Chemical Bonding Chemical Bonding – Atoms and molecules can come together to form complex molecules needed for life. Atoms of elements share electrons and this makes them “stick” together.

6. Chemical Bonding Bonds hold elements together to form compounds. Can you list examples of compounds?

7. Chemical Bonding The compound pictured below is very important to life on Earth. Do you know what it is? Hint: Autotrophs make this molecule and use it to preform the life process of respiration.