00:00Write a symbol for an atom with 10 protons and 12 neutrons, and an atom with 42 protons and 56 neutrons.
00:14Okay.
00:17Here's an atom.
00:21The atomic nucleus is composed of positively charged protons and uncharged neutrons.
00:26The particles that make up the atomic nucleus are known as nucleons.
00:33Therefore, the number of nucleons is the sum of the protons and neutrons.
00:41Surrounding the atomic nucleus are electrons.
00:45In a neutral atom, the number of electrons is equal to the number of protons.
00:50For identification, the atomic nucleus is given a specific letter symbol.
00:59Think of it as X.
01:03Next, the number of protons is written as a subscript to the left or right of X.
01:10Usually to the left.
01:11Meanwhile, the number of nucleons is written as a superscript to the left or right of X.
01:22This is the atomic symbol.
01:25Thus, the atomic symbol can be written as follows.
01:30The Z value is known as the atomic number.
01:32And the A value is known as the mass number.
01:48In the case of A, the atomic number is the number of protons.
01:54So, Z equals 10.
01:56The number of neutrons, A minus Z equals 12.
02:04Plugging in the value of Z.
02:08E equals 22.
02:11Think of it as atom X.
02:14This is the symbol for atom X.
02:20In case B, the atomic number is the number of protons.
02:24So, Z equals 42.
02:29The number of neutrons, A minus Z equals 56.
02:36Plugging in the value of Z.
02:38E equals 98.
02:43Think of it as atom X.
02:46This is the symbol for atom X.
02:51Hopefully, this is helpful.
02:54And don't forget to watch the next video.
02:56See you next time.
