00:01
Alright, so we want to determine the number of protons, neutrons, and electrons in some neutral atoms.
00:08
So protons, neutrons, and electrons.
00:12
For part a, we have bromine 79.
00:15
So to determine the number of protons in any of these, we can just look up the atomic number.
00:19
That's by definition the number of protons, so that's going to be 35.
00:23
To determine the number of electrons, that's also the same as the number of protons because it's the neutral atom, so we have equal amounts of positive and negative.
00:30
For the number of neutrons, we take the mass number given, which is 79, minus the atomic number 35, so this comes out to 44.
00:41
Alright, for part b, we're considering cesium -133.
00:46
Let me just write these all out.
00:48
C, d, wait, that's not b.
00:55
They're labeled, they're ordered wrong.
00:57
B is bromine 81, so that's a.
01:09
C, okay, c is plutonium -239.
01:12
D is cesium -133...