Classifying Matter

Quick Review Those itty bitty particles of matter? Do you remember their name? The basic building block of all matter? ATOM

Matter EVERYTHING! All matter is made of atoms If it has mass and occupies space then it is matter and made of atoms You, the air, your desk, your book, your pencil, your dog, your cat, your food, your teacher, your school, the trees, your house, the dirt, rocks, and even the vacuum cleaner that you are supposed to use to clean your room – but never do! EVERYTHING! (Except Energy)

Classifying Matter ELEMENT COMPOUND Just like the letters of the alphabet are the building blocks of words – atoms are the building blocks of matter Atoms are put together to form different types of matter, just like letters are put together to form different types of words If the matter is made of the same type of atom, it is called an ELEMENT If the matter is made of 2 or more kinds of atoms joined chemically, it is called a COMPOUND

Models of Atoms Since we cannot see an atom, we can use models. For instance: You will notice that each container only has one type of particle, or atom Some atoms always have a buddy, some are loners. These containers contain elements How can you tell?

Models of Compounds These containers illustrate compounds – 2 or more different atoms, or elements Atoms aren’t really different colors, but it makes the models easier to understand. Can you figure out how many different elements are in each container?

Check Understanding Can you figure out what is in each container? Look closely. Do you see elements, compounds, or both?

Elements There are 90 naturally occurring kinds of atoms. These are called elements Scientists in the lab have been able to make about 25 more (not naturally occurring) Is there a list or a chart or a table? OF COURSE

Elements Elements are represented by a symbol of 1 or 2 letters. The 1st letter is always upper case, the 2nd is always lower case Some symbols are easy to remember Others not so easy

Compounds Compounds are represented by 2 or more elements Which box would represent H2O? CO2?

Pb O2 HCl H2SO4 Element or Compound? How can you tell if a substance is an element or a compound when written in letters? Count the number of capital letters! If there is only one – it is an element If there is more than one – it is a compound Let’s try some….. Pb O2 HCl H2SO4

Chemical Change EQUATION How do elements become compounds and how do compounds become elements? Remember: in a chemical change, new substances are formed with different properties. Scientists have a special way of explaining chemical changes. It is called an EQUATION

Chemical Equations Are Easy! The reactants are the elements or compounds you begin with The products are the elements or compounds you end with The before and after are separated by an arrow. For instance: Sodium combines with chlorine to produce sodium chloride, or salt In scientific shorthand it is Na + Cl NaCl

Your Turn Write a Chemical Equation Write a chemical equation for each of these. Indicate which are elements and which are compounds. Hydrogen (H2) reacts chemically with oxygen (O2) to produce water (H2O) When the reactants, carbon (C) and oxygen, undergo a chemical change, carbon dioxide (CO2) is produced Sugar (C6H12O6), with the help of oxygen, is broken down by the body to produce carbon dioxide and water.

This equation illustrates a chemical reaction or chemical change. Your Turn Again! This equation illustrates a chemical reaction or chemical change. Write this equation in words. Indicate what substances reactants, products, elements and compounds.

Remember Elements and compounds can be represented by symbols or formulas Elements are only one kind of atom, and compounds are one or more elements or kinds of atoms. Chemical equations are a scientists’ shorthand for explaining a chemical reaction/change. When matter undergoes a chemical change, new substances are formed with different properties.

Output Page Idea Like using the letters of the alphabet to make words, can you use the symbols for the elements to make words? Use your Try to This can be OOOHH! If have one:

Questions?