* Matter is all around you * It is anything that has mass (the amount of stuff) and volume (occupies space) * Exists in four different states or phases * It is made up of atoms, molecules and ions

* Atoms or molecules are closely packed together and have the lowest kinetic energy * Often hard and brittle * Cannot often change their shape * Add heat and increase the KE, you can change the state

* Atoms or molecules can now move relative to each other * Liquids can ‘flow’ at room temperature * Have more KE and do not have a specific shape but will conform to the container it is in * Add more heat…

* Molecules or atoms are widely spread apart * They move freely in the space they are in and can move with high speeds * They can bump into one another and just bounce off instead of joining together * These have the highest KE

May be new to you Add even more energy and the electrons and neutrons can separate from one another and a ‘soup’ of positive ions and negative electrons are formed This is the plasma state

* When you add energy and you change the phase of a substance, this is called a physical change as you have NOT changed what the material is, just its state * Melting ice to water * Ripping a piece of paper, crushing a can * A physical change affects the form of a substance but not its composition and they are generally reversible

* Fireworks – Matches – Creating Precipitates * These occur on the molecular level and produces a new substance with different chemical properties from the original substances. * Are usually irreversible – can’t relight a match! * Heat/light may be released, color change may occur, an odor may occur, gas bubbles could be produced, sound can be created

* The smallest unit of matter is the atom * The smallest particle of matter that retains its chemical properties * Consists of three particles

* Positive particles * Found in the nucleus of the atom * Have a charge of +1 * Have a mass of 1amu (atomic mass unit) * The number of protons in an element is the same as the atomic number of that element

* Negatively charged particles * Found in an area outside the nucleus called the electron cloud * Have no mass * Have a charge of -1 * In a neutral atom there are an equal number of protons and neutrons so that the net charge is zero (0)

* Particles without a charge * Found in the nucleus * Have a mass of 1 amu * The total atomic mass of an element id the number of protons added to the number of neutrons

* Oxygen is the element * 8 is the atomic number * 16 is the atomic mass * How many protons? * How many electrons? * How many neutrons? * Answer =

* The element is sodium * The atomic number is 11 * The atomic mass is 23 * How many protons, electrons and neutrons?