00:03
Hi there.
00:04
In this question, we want to know how many protons, electrons, and neutrons we have in this sulfur ion.
00:11
So i want to write the symbol for sulfur.
00:13
And looking at the periodic table, i see it as atomic number 16.
00:17
So i'm going to put that there.
00:19
We are told its mass number is 34.
00:22
And its charge is two negative.
00:25
It's an ion.
00:27
Okay.
00:27
So let's go ahead and start tackling this.
00:31
First of all, let's start with the atomic number.
00:35
By definition, the atomic number is the number of protons.
00:42
This is true for every atom or ion on that periodic table.
00:48
The atomic number is always the number of protons in the nucleus of every atom or ion of a specific element.
00:57
Therefore, this is going to have 34 protons, or i'm sorry, 16 protons.
01:03
Getting ahead of myself here.
01:04
Atomic number 16, therefore 16 protons.
01:11
All right.
01:14
Next, let's go ahead and define that number 34 there, that mass number.
01:19
34 is the mass number for this element, or for this isotope, i guess i should say.
01:25
And mass number is equal to the number of protons plus the number of neutrons.
01:37
All right, so number of protons plus the number of neutrons.
01:42
Well, our mass number is 34.
01:45
That is given to us.
01:47
And we already determined that the number of protons are 16.
01:51
So 16 plus the number of neutrons is 34.
01:55
So we subtract 16 from each side here...