If the atomic number is # of protons, why does emission of a beta (electron) particle increase the atomic number?

Atomic number: the number of protons in the nucleus of an atom, which is characteristic of a chemical element and determines its place in the periodic table.

Beta emission:

$$\ce{^14_6C -> ^14_7N + ^0_{-1}\beta}$$

Why does emission of an electron increase the atomic number, when the atomic number is the number of protons, not electrons?

• In a beta decay a proton may change into a neutron. Or a neutron may change into a proton. www2.lbl.gov/abc/wallchart/chapters/03/2.html – CoffeeIsLife Jan 14 '17 at 23:33
• Maybe you are confusing it with alpha decay? – CoffeeIsLife Jan 14 '17 at 23:35
• Thanks for the answer. It makes sense now. I forgot the part about a neutron changing into a proton. I thought the change in number of protons had something to do with a proton being a + and an electron being a -, rather than a loss of an electron converting a neutron into a +. – K-Feldspar Jan 14 '17 at 23:44