Atoms UNIT 2 – Lesson 2 Notes

Matter All matter is made up of tiny particles called atoms. There are many different types of atoms. Most things are a mixture of atoms. 2

Matter Elements are pure substances made up of only ONE type atom. They are the simplest form of matter! Living things are not ELEMENTS, because they are made up of a combination of atoms: Oxygen Carbon Hydrogen Nitrogen Sulfur Phosphorus 3

Identify an Element So many to choose from…

https://www.youtube.com/watch?v=zGM-wSKFBpo

Building Blocks proton neutron electron Three basic particles make up an atom: protons, neutrons, and electrons. Protons and neutrons make up the nucleus of an atom. Electrons orbit around the nucleus. proton neutron electron

Building Blocks _ + cHaRgEs + _ Protons – particles that have a positive electric charge (+) Neutrons – particles that have a no electrical charge (0) The nucleus has a positive charge Electrons – particles that have a negative charge (-) _ + + cHaRgEs + _

Building Blocks The number of protons determines what element it is! When you add protons to the nucleus, you change the element.

Reading the Periodic Table Atomic number – the number of protons in an atom’s nucleus. Each element has a certain atomic number. This also equals the number of electrons in the atom’s electron cloud. Atomic Number Element

Reading the Periodic Table Atomic Mass– the number of protons and neutrons making up an atom’s nucleus. Atomic Number Element Atomic Mass 11

Atomic Number Element Atomic Mass number of protons as well as electrons Element Atomic Mass number of protons and neutrons combined

Isotopes Isotopes – atoms of the same element that have different numbers of neutrons. proton neutron electron

About Electrons Electron shells are the “clouds” around the nucleus where the electrons move. The first shell can only hold 2 electrons Shells outside of the first can hold 8 electrons The outer most shell is called the valence shell Na 14

Simple Science: What is an ATOM YouTube / Video Link