The Matter of Facts! Matter Anything that has mass and takes up space. Everything around us is matter! So what’s the matter? It’s a matter of fact(s)! Identifying Matter What’s the matter? Physical Properties of Matter Physical properties are characteristics of a substance that can be observed or measured without changing the substance into something else. •Color •Hardness •Taste •Length •Width •Height •Weight •Mass •Volume •Density •Ability to conduct heat, electricity, or sound •Ability to become a magnet Mass – The amount of matter in an object. Scientists use a balance scale to measure mass. The object’s unknown mass is compared to a known mass. Mass is recorded in grams or kilograms Weight – A measure of the pull of gravity on an object. So…do you think your weight is the same on Earth as it is on the moon? Your weight is approx. 6 times less on the moon because the gravitational pull is 5/6 less than on earth! So to find your weight on the moon, divide your weight by 6 What are some of the physical properties of these boxes? Can you find ways to tell these apples apart? Circumference The distance around a circle. Much like the perimeter, only around something round – like an apple! Volume Volume – The amount of space an object takes up. Volume = length X width X height V=lxwxh expressed in cubic units Simple enough when it is a box, but what if the solid is irregular? What if you wanted to know the volume of an apple? What then? Volume can be found by measuring Displacement Measurement of the amount of liquid that a solid displaces. 1cu3=1ml - You can use a graduated cylinder such as one of these! How you ask? When using a graduated cylinder to measure, you must be careful to measure the bottom of the level of liquid. This curved look of the liquid is known as the meniscus. Density Concentration of Matter in an object Density equals mass divided by volume States of Matter No, not those states, these states….. 3 States or Phases of Matter Solid: •Has a definite shape •Has a definite volume •Molecules are very close together Liquid: •Does not have a definite shape (will take the shape of a container) •Has a definite volume •Molecules are a little further apart and vibrate a bit quickly Gas: •Does not have a definite shape (will take the shape of a container) •Does not have a definite volume •Molecules are very far apart and vibrate very quickly! Plasma (yes, this too is a state of matter, but you’ll learn more about this later!) • No definite shape or volume • Particles broken apart The changing of the states or phases of matter Changes in state are physical. They do not change the substance. Changes in state are reversible! •Freezing - liquid to solid •Melting - solid to liquid •Boiling - liquid to gas •Condensation - gas to liquid •Sublimation - solid to gas •Evaporation - when particles escape from a nonboiling liquid and become a gas Melting and Boiling Points Melting Point & Freezing Point are the same! Water freezes at 0C or 32F Boiling Point Temperature at which a substance changes from a liquid to a gas. Water boils at 100C or 212F Mixtures Combination of 2 or more different kinds of matter that keep their own physical properties and can be easily separated. Solution - Type of mixture in which particles of 2 or more substances are mixed and not easily separated. Solubility - the ability to be dissolved. Solutions are not easily separated Sugar is soluble in water. Pepper is not! Suspension - a mixture of liquids with particles of a solid which may not dissolve in the liquid. The solid may be separated from the liquid by leaving it to stand, or by filtration Examples: oil in water sand in water Chemical Changes or Reactions of Matter Changes in which one or more new substances are formed are called chemical changes or reactions. Marshmallow melting is physical change. Marshmallow burning is a chemical change Sodium + Chlorine = Sodium Chloride (Salt) These are examples of chemical change or reaction because light or heat or both are produced. Burning Candle Reactivity - The ability of a substance to react chemically Clues that identify chemical change: •Change in color •Production of light •Production of heat •Production of a gas Chemical Change Example! Baking soda + vinegar = gas Carbon dioxide is produced Chemical Change Example! Burning Candle - heat and light are produced Chemical Change or Reaction Iron rusting is an example of chemical reaction or change A change in color occurs Iron conducts electricity Rust does not conduct electricity Different densities Different melting points Combustibility Chemical property of being able to burn. Flame Test Used to identify substances based on the color of the flame they produce when burned. Law of Conservation of Matter Matter is neither created nor destroyed during a physical or chemical change. The amount of matter is always the same. The END for now….more madness to come later!