ABSTRACT
For the purposes of chemistry problems, the atom is composed of three major particles; the arbitrary symbols shown in the table are used throughout the chapter. The mass unit abbreviated as “amu,” the atomic mass unit, provides a convenient measurement of mass and is explained in detail in Chapter 3; 1 amu = 1.66054 × 10−27 kg
Particle
Symbol
Unit Charge
Mass (kg)
Mass (amu)
Proton
p+
+1
1.6726 × 10−27 kg
1.007276 amu
Electron
e−
−1
9.11 × 10−31 kg
0.0005486 amu
Neutron
n0
0
1.6749 × 10−27 kg
1.008665 amu
