Unit 4 - Material properties

04.13.2020
08:20:25
Dear students, good morning
Today's topic : material properties in Cambridge checkpoint science grade 9
Pg.no : 60 &61
Concept : The structure of the atom
The important points are
1.Atoms are made up of
Protons ,neutrons and electrons
2.particles arrangements
* Protons and neutrons are grouped closely together in the centre of atom.its called nucleus
* The electrons move around the nucleus
* Protons have positive electric charge
* Neutrons have no charge
* Electrons have negative electric charge
3. Scientists come up with the model of atom
For example
* J.J.thomson - plum pudding model
* Rutherford - gold foil experiment
So they helped us understand the structure of atom
No homework.
For better understanding of concepts watch the below videos