Subatomic Particles So Thats Whats in an Atom

The atom is the smallest part of matter that represents a particular element. For quite a while, the atom was thought to be the smallest part of matter that 

Scientists now recognize that there are many subatomic particles (this really makes physicists salivate). But in order to be successful in chemistry, you really only need to be concerned with the three major subatomic particles  

Name Symbol Chaise Mass(g Mass(aam) Location 

In Table 3-1, the masses of the subatomic particles are listed in two ways grams and amu, which stcinds for atomic mass units. Expressing mass in amu is much easier than using the gram equivalent. 

Atomic mass units are based on something called the Carbon 12 scale, a worldwide standard that s been adopted for atomic weights. By international agreement, a carbon atom that contains 6 protons and 6 neutrons has an atomic weight of exactly 12 amu, so 1 amu is Yu of this carbon atom. I know, what do carbon atoms and the number 12 have to do with anything Just trust me. Because the mass in grams of protons and neutrons are almost exactly the same, both protons and neutrons are said to have a mass of 1 amu. Notice that the mass of an electron is much smaller than that of either a proton or neutron. It takes almost 2,000 electrons to equal the mass of a single proton. 

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