INTRODUCTION PLUNGING IN ou step onto the pool's diving board It bounces a little as you take a few steps forward Right before you get to the edge you jump up You land on the board and it launches you into the air With arms up you take a deep breath as you are into the pool Then you slice into the cool water Not only did you just complete a perfect dive you also experienced several different states of matter The hard board is a rigid solid Your deep breath took in oxygen a gas And the We experience matter in its different states all the time Nearly everything around you is a solid a liquid or gas a
Water is an important and fun substance It has a solid form as well as a liquid form And it can also be a gas cool water you dove into is a liquid All three of these are made of matter Have you thought about why water can flow and freeze Or why wood turns to ash when it's burned Scientists wondered about these things too When scientists have questions they create theories and experiments to test their ideas The evidence they find leads to conclusions or answers about our world 5
CHAPTER 1 WHAT IS MATTER verywhere you look you'll see matter in its different states It's in a raindrop as liquid falling through the sky filled with gas It's in a tree trunk or a snowflake as solids It's even in you all the many parts of your body are made of matter In fact everything in the universe is made of matter If something has mass and takes up space then it's matter Snowflakes are delicate and melt easily But because they have a distinct shape they are solids considered
7 These states of matter seem very different but they all have something in common They are all made of tiny particles Democritus was a Greek philosopher who lived about twenty four hundred years ago He believed all matter was made of particles he called atoms He thought these atoms floated around and could also connect with other atoms using hooks But Democritus had no way to prove his theory DISCOVERING ATOMS Democritus believed that atoms were all the same but different shapes In the early nineteenth and positions of atoms made up century British teacher and different matter meteorologist John Dalton saw that water evaporates into air He wondered how water and air could both be in the same space But he thought that if water and air were
