Posts

Experiment of Air presence in soil

Image
 Experiment of Air presence in soil When, water and soil are mixed the height to the water level appears to be less than 8 cm. Imagine the height after water and soil are mixed is 6 cm. We can assume that the height of 4 cm of soil contains about 2 cm of air. That means about ¼ of the volume of soil contains air. The soil air amount in different soil samples is different. In the above activity water has moved into the space among soil particles. When, water moves into those spaces air present in them is released. Air which retains in soil particles is called soil air.
Post a Comment
Read more

Atmosphere - Grade 7 Science unit - 13

Image
Atmosphere   
1 comment
Read more

SPIDERS

Image
  Spiders                  Black widow spider Spiders are arachnids , not insects. Other members of arachnid family include Scorpion , mites and harvestmen. Spiders have 8 legs while insects have 6. Spiders don't have antennae while insects do. Spiders are found on every continent of the world except Antarctica. There are around 40 000 different species of spiders. Most spiders make silk which they use to create spider webs and capture prey. Abandoned spider webs are called cobwebs. Most spiders are harmless to humans but a few spider species, such as black widow, can bite humans and inject venom. Deaths from spider bites are rare however. An abnormal fear of spiders is called 'arachnophobia''
1 comment
Read more

Speech about Dr. C. W. W. Kannangara

Image
  Dr. C. W. W.  Kannangara  
Post a Comment
Read more

My School

Image
                   MY SCHOOL       My School is AL/Humaisara National School. It is located in western province, Kaluthara district, Beruwala divisional secretariat and China Fort.  It is a boys' school. It has about 2000 students and about 90 teachers are in my school. My school principal is Mr. M. R. M. Rifky. It has classes from grade 1 to 13. Our teachers are very kind and helpful. I am in grade 7A and my class teacher is Miss. Safra Zuhoor. We have to safeguard our school's properties. I love my school very much.                                                                                                 ...
6 comments
Read more