How to find the number of protons, neutrons, & electrons for an element on the periodic table.
Feb 09, 2016
How to find the number of protons, neutrons, & electrons for an element on the periodic table.
What is an element?
An element is a substance that cannot be broken down into simpler substances by ordinary physical or chemical means. Elements are known as the building blocks of matter.
It is made up of protons, neutrons, and electrons.
The periodic table is made up of elements.
Protons have a positive charge,
are located in the nucleus,
and have a mass of 1 amu.
Remember P +
Neutrons have a Neutral charge,
are also located in the nucleus,
and have a mass of 1 amu
Remember N
Isn’t this easy!
Electrons have a Negative charge,
are located on the shells around the nucleus,
and have a mass of 0 amu.
Nucleus
Shells
Electrons
Remember E-
1
HHydrogen
1.00794
The four parts of the periodic table are:
Atomic Number
Symbol
ElementAtomic Mass
(Weight)
What is the Atomic Number for Carbon (C)?
Quick Quiz
What is the Atomic Number for Iron (Fe)?
What is the Atomic Number for Potassium (K)?
What is the Atomic Number for Nitrogen (N)?
What is the Atomic Number for Gold (Au)?
What is the Atomic Number for Carbon (C)?
Quick Quiz
What is the Atomic Number for Iron (Fe)?
What is the Atomic Number for Potassium (K)?
What is the Atomic Number for Nitrogen (N)?
What is the Atomic Number for Gold (Au)?
6
79
7
19
26
Atomic Number
1
HHydrogen
1.00794
The Atomic Number equals the number of protons and electrons for that element.
Hydrogen has 1 proton
1 electron.
Atomic Number
6
CCarbon12.011
The Atomic Number equals the number of protons and electrons for that element.
Carbon has 6 Protons
6 Electrons
How many protons does Oxygen have?
Quick Quiz
How many protons does Calcium have?
How many protons does Zinc have?
How many protons does Tin (Sn) have?
How many protons does Radon have?
How many electrons does Oxygen have?
How many electrons does Calcium have?
How many electrons does Zinc have?
How many electrons does Tin (Sn) have?
How many electrons does Radon have?
How many protons does Oxygen have?
Quick Quiz
How many protons does Calcium have?
How many protons does Zinc have?
How many protons does Tin (Sn) have?
How many protons does Radon have?
8
86
50
30
20
How many electrons does Oxygen have?
How many electrons does Calcium have?
How many protons does Zinc have?
How many protons does Tin (Sn) have?
How many protons does Radon have?
We’ve learned about protons and electrons.What are we missing?
Atomic Number
1
HHydrogen
1.00794
The number of Neutrons equals the Atomic Mass minus the Atomic Number.
Atomic Mass
Atomic Mass- Atomic Number
Number of Neutrons
This sounds very complicated and I’m confused.
That’s O.K. follow these 2 simple steps to help you.
Atomic Mass- Atomic Number
Number of Neutrons
Step 1
1
HHydrogen
1.00794
Atomic Mass
Round the Atomic Mass to the nearest whole number.
1.00794Look at the tenths column.
If the number in the tenths column is 5 or greater, then round the number up, if not
leave unchanged.1.00794 rounded to the
nearest whole number is?
Step 2
1
HHydrogen
1.00794
Find the Atomic Number:
Take the rounded Atomic Mass
Subtract the Atomic Number
Equals the Number of Neutrons
Practice
7
NNitrogen14.0067
Take the rounded Atomic Mass
Subtract the Atomic Number
Equals the Number of Neutrons
Find the number of Neutrons in Nitrogen:
Practice 2
17
ClChlorine
35.453
Take the rounded Atomic Mass
Subtract the Atomic Number
Equals the Number of Neutrons
Find the number of Neutrons in Chlorine:
Practice 2
17
ClChlorine
35.453
Take the rounded Atomic Mass
Subtract the Atomic Number
Equals the Number of Neutrons
Find the number of Neutrons in Chlorine:
Practice 3
79
AuGold
196.9665
Take the rounded Atomic Mass
Subtract the Atomic Number
Equals the Number of Neutrons
Find the number of Neutrons in Gold:
Practice 3
79
AuGold
196.9665
Take the rounded Atomic Mass
Subtract the Atomic Number
Equals the Number of Neutrons
Find the number of Neutrons in Gold:
Directions: Find the number of Protons, Electrons, and Neutrons for each element listed below.
Boron (B)Protons -Electrons -
Neutrons -
Copper (CU)Protons -Electrons -
Neutrons -
Indium (In)Protons -Electrons -
Neutrons -
Plutonium (Pu)Protons -Electrons -
Neutrons -
Scandium (Sc)Protons -Electrons -
Neutrons -
Sulfur (S)Protons -Electrons -
Neutrons -
Directions: Find the number of Protons, Electrons, and Neutrons for each element listed below.
Boron (B)Protons -Electrons -
Neutrons -
Copper (CU)Protons -Electrons -
Neutrons -
Indium (In)Protons -Electrons -
Neutrons -
Plutonium (Pu)Protons -Electrons -
Neutrons -
Scandium (Sc)Protons -Electrons -
Neutrons -
Sulfur (S)Protons -Electrons -
Neutrons -
Now you know a little about the periodic table and how to find the number of protons, electrons, and
neutrons.