factoid...
Fact of the Day: atom, molecule
"Atoms make up all matter -- gases, liquids, and solids. It is the smallest unit of about 100 simple substances called elements. Atoms of the different elements may combine into systems called molecules. The atoms might be thought of as "building blocks" joined together to form the molecules. How small is the smallest unit of matter? The period at the end of this sentence has more than 400 million atoms. The atoms themselves are made of even smaller components called protons, electrons, and neutrons. Protons and neutrons are made up of even smaller particles called quarks. All atoms are about the same size, but they are have different components. An atom of hydrogen has just one proton. An atom of carbon has six protons, six neutrons, and six electrons. A molecule of water has two hydrogen atoms and one oxygen atom. The dense center of the atom is called the nucleus. Scientists learned how to split the nucleus, which releases an enormous amount of energy, thus creating nuclear power."
"Atoms make up all matter -- gases, liquids, and solids. It is the smallest unit of about 100 simple substances called elements. Atoms of the different elements may combine into systems called molecules. The atoms might be thought of as "building blocks" joined together to form the molecules. How small is the smallest unit of matter? The period at the end of this sentence has more than 400 million atoms. The atoms themselves are made of even smaller components called protons, electrons, and neutrons. Protons and neutrons are made up of even smaller particles called quarks. All atoms are about the same size, but they are have different components. An atom of hydrogen has just one proton. An atom of carbon has six protons, six neutrons, and six electrons. A molecule of water has two hydrogen atoms and one oxygen atom. The dense center of the atom is called the nucleus. Scientists learned how to split the nucleus, which releases an enormous amount of energy, thus creating nuclear power."