00:01
Let's determine the number of protons, neutrons, and electrons in the following.
00:05
So protons, for a, atomic number is nine.
00:08
So we have nine protons, neutrons, mass number is 18, minus the atomic number.
00:15
So i have nine neutrons, electrons charge of plus one.
00:21
So that means i have eight electrons.
00:24
For b, protons, neutrons, electrons, atomic number is 43, so that's the number of protons, number of neutrons, mass number is 99, minus 43, give me 56 neutrons and a charge of plus 7, so that would be 43 minus 7, 36 electrons.
00:53
For c, we've got atomic number, protons, neutrons, electrons, atomic number 53, so 53 protons.
01:08
Mass number is 131, so 131 minus 53 gives me 78 neutrons, charge of minus 1 means i have 54 electrons...