Take three test tubes .Fill in 3/4th of eacg with water.Label them A,BandC.Keep a snail in test tube A,a water plant in test tube B and in C ,Keep snail and plant both.Which test-tube would have the highest concentration of CO2?

Four test tubed marked I,II,III and IV were taken 20 ml of Al_2(SO_4)_3 solution in water was poured in each of the test tube I, an iron nails was put in test tube II, copper turnings were put in test tube III and a clean aluminium strip was placed in test tube IV. No change was observed in any four any in the test tubes. the correct inference drawn is

An empty test tube is placed slanting in the water and viewed from above, what will you observe?

Some yeast, sugar and water are mixed in a tes-tube. The diagram show the test-tube at the start and after one hour. Which process causes this change?

Equal lenghts of magnesium ribbons are taken is test tubes a and b hydrochloric acid (HCl) is added to test tube a, while acetic acid (CH_3COOH) is added to test tube b. amount and concentration taken for both the acids are same. In which test tube wil the fizzing occur more vigorously and why?