# What are the following familiar objects? How can you describe them if you didn't know what they were?

People describe objects in many ways using size, shape, colors, and textures. Describing objects by using

• size (place images here)
• shape
• color
• texture

uses an object's properties. A property describes how an object looks, feels, or acts. The objects shown here have different kinds of properties:

### The present is:

Properties of all objects

• Objects take up space.

All objects take up space. Your computer is taking up space on the desk. You are taking up space on the chair.

• Objects have mass.

Mass is how much there is of an object. Mass is related to how much something weighs. Mass and weight are two different things. The unit for mass is a gram. A nickel has the mass of about one gram.

Objects that take up space and have mass are called matter. Everything around you is made up of matter. Chocolate cake is made up of matter. You are made of matter.

If you are having trouble understanding matter, look all around you. You can see matter makes up the walls of your house and your classroom. Matter is large and matter is small. Do you get it yet?

Let's take this carrot:

Let's get closer and closer to the smaller parts of the carrot-carrot atoms!

These small parts of the carrot are called atoms. Anything you see and can feel is made of atoms. All atoms are too small to be seen with the naked eye or even a microscope, although there are some new types of microscopes that are now able to see larger atoms such as gold.

All matter is the same because all matter is made up of atoms. Matter is also different because objects can be made up of different kinds of atoms. Gold is made of one kind of atom-gold atoms. Salt is made up of two different kinds of atoms-sodium atoms and chloride atoms.

Properties of Matter

Remember all objects take up space and have mass. You use your sense of taste and smell to tell the difference between spinach and an orange.

Physical properties- The measurement of mass and other characteristics that can be seen without changing how that object looks are its physical properties. When you look at oranges, you know that they are oranges because of their color, shape, and smell. Mass, color, shape, volume, and density are some physical properties. The answers to the question about the present are physical properties.

Density is an important physical property. Density is the mass of a substance per unit volume. Volume is the amount of space an object occupies.

Chemical properties- These are properties that can only be observed by changing the identity of the substance. A piece of paper burns and turns to a black substance. After the flame goes out you can no longer burn the new substance. The chemical properties have been changed.

Properties are constantly changing...

Matter is constantly changing. Ice in your soda melts, glass breaks, paper is ripped. When ice in your soda melts where does it go? What does it become?

If you remember, ice is water in the solid state. If you don't remember this or don't know it, you should go back and review states of water. When you drop the ice cube into the liquid, it begins to melt because the temperature is higher than that of the ice cube. It's like putting a snowman on your front lawn in July. The ice cube becomes liquid water. This is an example of a physical change. The solid water turned to liquid water. It doesn't turn into soil or macaroni. It remains water. If it did change into soil or macaroni, your drink would taste terrible and you would have an example of a chemical change.

Chemical changes are changing substances into other substances. If it could happen, ice changing into macaroni would be an example of a chemical change. A real example of a chemical change is spoiling milk or burning toast. Milk needs to be in the refrigerator or else it will go bad. If you've ever seen or smelled spoiled milk, it is not a pretty sight. The milk gets a sour odor and becomes lumpy. Unlike physical changes, you cannot reverse chemical changes. You can melt ice to get water and freeze that water to get ice again. You cannot make milk unspoiled.

to Chapter 2- States of Matter

Pages and gif animations written and designed by Sheila M. Estacio. Please send comments, praises, gripes, questions to sme2446@is2.nyu.edu