Full transcript
What are atoms and the basic structure of atoms
0:00Atomic structure.
0:01In this video we are going to go over atomic
0:04structure in a very simplistic and basic way.
0:07Atoms are the basic unit of chemical elements.
0:09They contain subatomic particles in their nucleus and
0:13in the electron cloud that surrounds the nucleus.
Protons, neutrons and electrons
0:16These subatomic particles include protons and
0:18neutrons, which are located in the nucleus,
0:21and electrons, which are located in the cloud, or field that surrounds the nucleus.
0:27Protons have a positive electrical charge, neutrons
0:30are uncharged, and electrons have a negative charge.
0:33The number of protons and electrons are equal,
0:36so atoms are electrically neutral particles.
0:39If we look at a model of the element carbon, which has
Shells surrounding the nucleus
0:436 protons, 6 electrons, and in most cases 6 neutrons,
0:47we can see the electrons in simple rings or shells surrounding the nucleus.
0:52Each shell represents a different energy level,
0:55and it can only hold a certain maximum number of electrons.
0:58In chemical reactions between atoms, only the electrons in the
1:02outermost shell participate in the resulting chemical bond.
1:06In atoms with only one energy level or shell,
1:092 electrons are required for stability.
1:11If we look at helium, which has only 1 shell or energy level,
1:15we see that it is full, because it contains 2 electrons.
1:19So helium is stable,
1:21and there is no naturally occurring compound containing helium.
1:24Hydrogen, which also has only one ring or shell, possesses
1:29only one electron in its shell, so it is chemically reactive.
1:33In atoms with more than one energy level or shell, 8
1:36electrons are required in its outermost shell for stability.
1:40So, neon, which has 8 electrons in its outermost shell, is stable,
1:46and oxygen, which has only 6 electrons in its outmost shell, is chemically reactive.
1:52Atoms that do have fewer than 8 electrons in their outermost shells,
1:56will try to share, gain, or lose electrons in order to become stable.
2:02This is called the octet rule, but there are some exceptions,
2:06such as we saw with hydrogen and helium which only have one energy level or shell.
2:12And that, be the basics on atomic structure.