Question

Question #4a5cf

Answer 1

Alpha radiation.

Explanation:

Polonium-212 undergoes alpha decay to produce lead-208, which means that it gives off alpha radiation, i.e. alpha particles.

An alpha particle, `alpha`, is simply the nucleus of a helium-4 atom, which means that it contains

• two protons
• two neutrons

When a radioactive nuclide emits an alpha particle

• its mass number will decrease by `4`

The mass number, `A`, is given by the number of protons and neutrons, and so

`A = "2 protons " + " 2 neutrons" = 4`

• its atomic number will decrease by `2`

The atomic number, `Z`, is given by the number of protons, and so

`Z = "2 protons" = 2`

Now, the two elements that you're working here with have

`"Po: " {(A = 212),(Z = 84) :}" "` and `" " "Pb: " {(A = 208), (Z = 82) :}`

This confirms that you're dealing with an alpha decay because the balanced nuclear equation that describes this process looks like this

`""_ (color(white)(1)color(darkgreen)(84))^color(blue)(212)"Po" -> ""_ (color(white)(1)color(darkgreen)(82))^color(blue)(208)"Pb" + ""_ color(darkgreen)(2)^color(blue)(4)alpha`

Notice that mass and charge are conserved, since

`color(blue)(212 = 208 + 4) ->` conservation of mass

`color(darkgreen)(84 = 82 + 2) ->` conservation of charge