Atoms

Atoms

1. Atoms exist everywhere in everything including you

2. Atoms are so small that you can't even see them with an electric microscope.

3. An element of pure gold is made up of gold atoms

4. Atoms are the smallest things that exist in an elment

5. Atoms contain a dense nucleus surrounded by a cloud of electrons, which contain a negative charge

6. The interior of the nucleus contains positively charged protons, and almost all atoms' nuclei (with the exception of hydrogen-1) contain

7. It wasn't until the end of the 19th century and beginning of the 20th century that scientists began to discover subatomic particles contained within the atom

8. Nearly one hundred percent of the mass of an atom (99.94%) is contained in the nucleus.

9. Atoms are classified according to their numbers of protons or neutrons

10. Atoms are mostly empty space. The nucleus of an atom is extremely dense and contains nearly all of the mass of each atom. Electrons contribute very little mass to the atom (it takes 1836 electrons to equal the size of a proton) and orbit so far away from the nucleus that each atom is 99.9% empty space. If the atom was the size of a sports arena, the nucleus would be the size of a pea. Although the nucleus is much more dense compared with the rest of the atom, it too consists mainly of empty space.