Response:
How can you differentiate a physical change from a chemical change?
Clarification:
145 hours.
Explanation: Riding a bicycle for one hour expends 505 kcal of energy. Given that one gram of body fat equals 7.70 kcal, and 1 pound of body fat is equivalent to 454 grams:
1 lb = 454 g; thus, 21 lb = 21 × 454/1 = 9534 g. Moreover, converting 9534 g of body fat gives us 9534 × 7.70 kcal/1 = 73411.8 kcal. If riding for one hour burns 505 kcal, then to lose 73411.8 kcal, it would require 73411.8 kcal x 1 hour/505 kcal = 145 hours.
False, it's solely heterogeneous. Explanation: The degradation of the ozone layer caused by CFC molecules happens in the gaseous state since it does not involve liquids or solids at stratospheric conditions. Additionally, the reaction occurs independently as ozone is chemically unstable, eliminating the need for a catalyst.
O2 and O3 represent different forms of Oxygen; therefore, they exhibit (4) distinct chemical and physical properties..
