00:01
So we have various designations of elements with their symbols and the number of neutrons that each one contains.
00:14
And we're asked to show the complete symbol with the element symbol, the number of protons, and the number of neutrons.
00:24
And i'm sorry, i said number of neutrons.
00:27
That would be the sum of the number of protons of neutrons.
00:30
That is a, the subscript to the left, is the mass number, and the mass number is equal to the number of protons plus the number of neutrons.
00:41
So we first use the symbol to find the element on the periodic table, and we find that boron is number five, and that indicates that it has five protons.
00:53
And so symbol and number of protons as the subscript on the left.
01:00
And then to complete it, we want the sum of the number of protons and the number of neutrons.
01:08
And so that would be boron with five neutrons.
01:12
Then likewise, magnesium is number 12...