# Question bc45b

May 2, 2017

$\text{_82^211"Pb" → ""_83^211"Bi" + ""_text(-1)^0"e}$

#### Explanation:

It's difficult to read your question. I assume that you want to balance an equation like this:

""_82^211"Pb" → ""_83^211"Bi" + ""_text(?)^??

The main things to remember are:

• The sum of the subscripts must be the same on each side of the equation.
• The sum of the superscripts must be the same on each side of the equation.

Subscripts

82 = 83 + ?
? = "82 - 83" = "-1"

This gives

""_82^211"Pb" → ""_83^211"Bi" + ""_text(-1)^??

Superscripts

211 = 211 + ?
? = "211 - 211" = 0

This gives

""_82^211"Pb" → ""_83^211"Bi" + ""_text(-1)^0?#

Identify the particle

What particle has a charge of -1 and a mass near zero? An electron (or beta particle)!

The complete equation becomes

$\text{_82^211"Pb" → ""_83^211"Bi" + ""_text(-1)^0"e}$