Did you know that the average human nose can recognize about 10,000 different smells? Pretty amazing, huh!?

Nature of Matter What is Chemistry?? hmmm

Describing Matter Properties of Matter What is Matter? Matter – anything that has mass and takes up space. (remember that the amount of space something occupies is its volume)

Some types of matter are substances and some are not. Substance a single kind of matter that is pure and a specific set of properties. (Pure = always has a specific makeup or composition)

Describing Matter Physical Properties a property of matter that can be observed w/out changing the identity. ex. Color, odor, mass, volume, state, and…..

Thermal conductivity – ability to transfer thermal energy Thermal conductivity – ability to transfer thermal energy Malleability – can be pounded into sheets (aluminum foil) Malleability – can be pounded into sheets (aluminum foil) Ductility – can be drawn or pulled into a wire. Ductility – can be drawn or pulled into a wire. Solubility – can dissolve in another substance Solubility – can dissolve in another substance

And Density – mass per unit volume And Density – mass per unit volume Formula D = m/v Density of one substance is usually different from another. Most Dense Liquids have a higher number and are located at the bottom

Good Egg vs Bad Egg Density of Good Egg = 1.2 g/ml Density of Bad Egg =.9 g/ml Density of water = 1.0 g/ml Result Bad Egg Floats

Physical vs Chemical Changes Physical Change – does not form a new substance (most can be undone) Chemical Change – does form a new substance CANNOT BE UNDONE

Chemical changes often involve: Color changes Color changes Fizzing/foaming Fizzing/foaming Heat Heat Sound/light Sound/light Odor Odor

Chemical Properties One substances ability to change into a new substance w/ different properties. i.e. Wood burns and becomes smoke & ash

Chemical Properties Flammability – ability to burn Flammability – ability to burn Non-flammability – cannot burn Non-flammability – cannot burn Reactivity with - gas Reactivity with - gas acid acid water water

Elements An element is a pure substance that cannot be broken down into any other substances. !!!!Elements are the purest substances!!!!

Elements composed of atoms. Atoms combine to form molecules by creating chemical bonds. Compounds – a pure substance made of two or more elements chemically combined in a set ratio. (different properties than single elements) H 2 O

Mixtures – made of two or more substances not chemically combined. Heterogeneous - you can see the different parts Homogeneous – evenly mixed that you cannot see the different parts. A solution is an example.

Mixture Separation Magnet Magnet Filtering Filtering Distilling Distilling Evaporation Evaporation

What is Energy Energy is the ability to do work…. Energy is the ability to do work…. –And that work causes an object to move in the direction of the force. –It is expressed in units called Joules (J)

Forms of Energy 1. Thermal – is the total K.E. of the particles of an object (from hot to cold) 2. Chemical – energy required to bond matter particles together (toasting marshmallows) Thermal Imaging Chemically bonded atoms

Endothermic vs Exothermic Endothermic – energy is absorbed i.e. Melted cheese sandwich – the cheese takes in energy to melt. The sun is also endo- thermic.

Exothermic – energy is released i.e. Welding of any kind releases energy in form of sparks and heat

Endo vs Exo Graphs Endothermic Reaction

Electromagnetic energy- Electromagnetic energy- form of energy that travels thru space as waves. Electrical energy – energy of electrically charged particles moving from one place to another. Electrical energy – energy of electrically charged particles moving from one place to another.