Posted by anna on .
how to write a nuclear equation for the nuclear decay of Ra226 to an isotope of radon222

chemistry 1405 
DrBob222,
_{88}Ra^{226} ==> _{86}Rn^{222} + _{y}X^{z}
You want to determine y and z and X
Subscripts must add up and superscripts must add up.
Subscripts: On the left we have 88. On the right we have 86; therefore, y must be 2.
Superscripts: On the left we have 226 and on the right we have 222; therefore, z must be 4.
Which particle has a mass of 4 and an atomic number of 2? That must be He so that's X.
See how easy that is.