|
|
עמוד:5
The Particles of Matter : Atoms and Molecules An apple , a car , a rock , a cat , water – all objects in the world are made of matter , and matter is made up of atoms * . Atoms are very tiny – a single grain of sand or salt contains billions of billions of atoms ( about 10 ) . This is why the atoms cannot be seen with the naked eye or through a simple microscope . It was only in the 20 century that scientists succeeded in “ seeing” atoms using microscopes able to magnify the observed object a million times or more . Atom – the smallest particle component of matter . Micrometer – one millionth of a meter ( 10 -6 of a meter ) About 3 million carbon atoms fit into the width of this line , drawn by pencil ( Pencil is made of graphite , which consists of carbon atoms ) .
|
|