The nucleus is not of primary importance to chemists because the chemistry of atoms is generally determined by the number and arrangements of their electrons.
And electrons of course, are found outside of the nucleus.
But the nucleus and its chemistry has a big impact on our society.
➞ contains protons and neutrons.
➞ is very small
What is meant by "small" you say?...
Size of the Nucleus
Well a nuclear radius is roughly 10-13 cm.
If a nucleus were the size of a ping-pong ball, the nearest electron (the 1s1 e-) would be 0.30 miles away!
In addition to being extremely small, the nucleus is also very dense.
Density of the Nucleus
➞ density = on average: 1.6 x 1014 g/cm3 !!
Compare this to something we think as being "really dense" = lead (Pb), which is 11.3 g/cm3.
Here, let me help you understand...
Density of Lead Weight: 11.3 g/cm3
Density of Nucleus: 160,000,000,000,000 g/cm3
That "ping-pong ball" sized nucleus we mentioned earlier?
Um.... it would weigh 2.5 million tons!!
Nuclear Chemistry - Key Terms
The energies involved in nuclear processes (reactions) are millions of times larger than typical chemical reactions
Nucleons = a particle in the atomic nucleus; either a proton or a neutron.
Atomic Number (Z) = the total number of protons.
Mass Number (A) = sum of the number or protons and the number of neutrons.
Isotopes = atoms of the same element, having the same number of protons but different numbers of neutrons.
Nuclide = term used to describe a particular isotope.
In the example above, carbon-14 is a nuclide of carbon.
Many nucleii are radioactive, which means they can decompose, forming another nucleus and producing one or more other particles.
Here's an example of a typical radioactive decay reaction...
Radioactive Decay Example
Notice that the Z and A values must be conserved on each side of the reaction arrow.
➞ On the left and on the right, A = 14 (total).
➞ On the left and on the right, Z = 6 (total).
In my next post covering SECTION 19 - The Nucleus and Nuclear Chemistry,
We'll talk all about the Different Types of Radioactive Decay Reactions...