D.S.Q. 1. All substances are made up of particles which are too small to see. What are these particles called? Atoms 2. What are the different kinds of atoms called? Elements

Discussion What element has the symbol B? Boron What element has the symbol Na? Sodium What element has the symbol K? Potassium

Element Symbols Procedure 1. Write the word “BOOK” in your lab journal. With your class, look up the element names for each symbol in the word and list the element names. 2. Write the name “Cesar” in your lab journal. Look up the element names for each symbol in the word and list the element names. 3. Write your own name in your lab journal and try to spell it using element symbols. 4. Write as many words as you can using element symbols. Each word spelled must be followed by a list of each element name used in the word.

Combining Atoms Activity Procedure 1. Use the Periodic Table and analyze the chemical formula to construct a model of each molecule with snap together cubes. 2. Fill in the number and type of each atom in the molecule in the substance composition column. 3. Fill in the boxes provided with the color noted in the KEY to represent the model.

Matter

Measuring Matter Which weighs more, a pound of feathers or a pound of sand? Weight is a measure of the force of gravity on an individual. The force of gravity is greater on Earth than it is on the moon.

Measuring Matter How can you weigh less on the moon than on Earth when nothing about you has changed? Your weight depends on the gravitational force, however, your mass stays the same. Mass is the amount of matter in an object. Therefore, if you were to travel to the moon, the amount of matter in your body DOES NOT change

Mass The SI unit for mass is the Kilogram (kg) Grams are also used to measure smaller units of mass How do we convert grams to kilograms? There are 1,000 grams in a kilogram. Or kilograms in a gram. Kg = G ÷ 1,000 G = Kg x 1,000

Now you try! ObjectMass (g)Mass (kg) Nickel Baseball150 Pineapple1,600 Full can of soda390 Inflated balloon3

Answers

Volume The amount of space matter takes up Solids, liquids AND gas all have volume! The SI unit for volume is cubic meter (m³) Other common units are: Cubic centimeters (cm³) Liters (L) Milliliters (mL)

How is density determined? Density is a measure of the mass of a material in a given volume. You can find the density of a material by dividing its mass by its volume Which objects will sink, which will float? A block of wood and a block of iron Wood would float, iron would sink because wood is less dense than water and iron is more dense than water Density is a physical property

Changes in Matter

What happens to a substance in a physical change? A physical change alters the form or appearance of matter but does not turn any substance in the matter into a different substance.

Examples of Physical Changes melting point electrical conductivity colordensity boiling pointthermal conductivity odorhardness

Changes of states How many states of matter are there? 3-solid, liquid and gas. Suppose you leave a small puddle of liquid water on the kitchen counter. When you come back two hours later, the puddle is gone. What happened to the water? A physical change happened. The liquid water changed into water vapor (gas)

What happens to a substance in a chemical change? Chemical change or a chemical reaction is a change in matter that produces one or more new substances In some chemical changes, a single substance breaks down into two or more substances Example: Hydrogen peroxide breaks down into water and oxygen gas when poured on a cut Photosynthesis is a natural chemical change

Chemical Vs. Physical Change

Example of Chemical Changes

Law of Conservation of Mass French chemist, Antoine Lavoisier, discovered that matter is not created nor destroyed in any physical or chemical change Example: Suppose you could measure all the carbon dioxide and water produced when methane burns. What do you notice about the mass in the beginning and at the end? Is it the same amount of different?

How are changes in energy and matter related? What is energy again? The ability to do work Every chemical and physical change in matter includes a change in energy. Energy is NEVER created nor destroyed. It can only be transformed from one form to another

Temperature & Thermal Energy Temperature is a measure of how hot or cold something is. Temperature and energy are related For instance, the particles in warm air have greater energy, than the particles in cold air Thermal energy is the total energy of the motion of all of the particles in an object Thermal energy flows from warm cold

Thermal Energy & Changes in Matter Thermal energy is a form of energy that is released or absorbed Example: ice absorbs thermal energy from its surroundings when it melts and leaves the surrounding feeling cold. The melting of ice is an ENDOTHERMIC CHANGE, a change in which energy is absorbed Endothermic reactions usually feels cold because it is taking heat away from you. An exothermic change releases energy Exothermic reactions usually feels hot because it is giving heat to you

Red=Endo…..Blue=Exo

Examples: Exothermic ProcessesEndothermic Processes freezing water solidifying solid salts condensing water vapor making a hydrate from an anhydrous salt forming an anion from an atom in the gas phase Annihilation of matter E=mc 2 splitting of an atom melting ice cubes melting solid salts evaporating liquid water making an anhydrous salt from a hydrate forming a cation from an atom in the gas phase splitting a gas molecule separating ion pairs cooking an egg baking bread