Cornell Notes for the Atom• Set up your paper in Cornell note fashion (don’t forget to date

your paper). Use a sheet of looseleaf paper, we will glue them into your inb tomorrow.

• The topic is “Atoms”• The essential questions for slide 2 is “What is everything in the

Universe made of?”• The eq for slide 3 is “What is inside the nucleus of the atom

and what charges do they have?”• The eq for slide 4 is “What is outside of the nucleus of the

atom and what charge does it have?”• Don’t forget to complete a summary, and to circle key

vocabulary (in red), to underline main ideas (in green).

Introduction to atoms

Every thing in the Universe is made of matter. All matter is made of up atoms. Atoms are made of tiny particles. Atoms are so small that the human eye can’t see them, even with a microscope. They know that atoms exist because they are made up of charges (positive and negative). When they send rays of the opposite charge onto to parts of an atom, the rays bounce back. If there were no charges, the rays would just shoot straight through. That is how they know atoms exist.

Parts of the Atom:• All atoms have a nucleus in the center. The nucleus is made up

of two different particles, protons and neutrons. • Protons- you can determine the number of protons in an atom

by looking at the atoms atomic number on the Periodic Table of the elements. If the atomic number is 1, then the atom has 1 proton. If the atomic number is 116, then the atom has 116 protons. Protons have a positive charge.

• Neutrons- you can determine the number of neutrons in an atom by rounding the atomic mass number of the atom, and subtracting the atomic number from it. Ex: the atomic mass number for Carbon is 12.011. This rounds to 12. The atomic number for Carbon is 6. You would subtract 6 (at #) from 12 (rounded at mass #) to get the number of neutrons (6). Neutrons are neutral and have no charge.

Parts of the Atom (cont.)• Outside of the nucleus, the electrons can be found. You can

determine the number of electrons in an atom by looking at the atomic number. If the atomic number is 24, then the atom will have 24 electrons. Electrons have a negative charge.

• Electrons are found in energy levels. The first energy level can only hold 2 electrons (once it is full, remaining electrons carry over to the next energy level). The second energy level holds up to 8 electrons (once it is full, remaining electrons carry over to the next energy level). The third energy level holds up to 18 electrons. The fourth energy levels holds up to 32 electrons. The fifth energy level holds up to 50 electrons. The sixth energy level holds up to 72 electrons.

Complete the following for class tomorrow.• Name of atom: Oxygen Atomic # is 8, Atomic Mass # is

15.9994. How many protons does it have? How many neutrons? How many electrons?

• Name of atom: Hydrogen Atomic # is 1, Atomic Mass # is 1.0079. How many protons does it have? How many neutrons? How many electrons?

• Name of atom: Argon Atomic # is 18, Atomic Mass # is 39.948. How many protons does it have? How many neutrons? How many electrons?

• Don’t panic if you are not understanding the notes yet, we will go over them in class.