Unit 4 - Material properties

04.15.2020
08:46:41
Dear students, good morning
Today's topic : Mass number and atomic number
Pg.no : 62 in Ur cambridge check point science grade 9
The important points are
1.Atomic number says how many protons are in the atoms
2.Mass number tells you how many protons + neutrons there are
for example : Lithium
* Atomic number = 3
* mass number = 7
* Number of protons = 3
* Number of neutrons = 4
No homework
For better understanding of concepts watch the below video