Answer:
Yes, it underwent a chemical change
Explanation:
Answer:
The solid crystals disappeared
Explanation:
When a soluble solid solute is added to water, the solid solute disappears after a little while. The disappearance of this solute indicates that the solute has been dissolved in water.
In this case, blue copper sulphate crystals are added to water, the blue crystals disappear leaving only a blue solution. The disappearance of these blue copper sulphate crystals indicates that the substance has dissolved in water.
Answer:
0.625 g
Explanation:
Given data:
Half life of radon-222 = 3.8 days
Total mass of sample = 10 g
Mass left after 15.2 days = ?
Solution:
Number of half lives = T elapsed / Half life
Number of half lives = 15.2 / 3.8
Number of half lives = 4
At time zero = 10 g
At first half life = 10 g/2 = 5 g
At 2nd half life = 5 g/ 2= 2.5 g
At third half life = 2.5 g/2 = 1.25 g
At 4th half life = 1.25 g/2 = 0.625 g
Carbon dioxide and Water are the products of cellular respiration.