Answer: The solution to the problem expressed to he correct number of significant figures is 1.69
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
The rule applied for multiplication and division is :
The least precise number determines the number of significant figures in the answer.
As 12.0 has 3 significant digits and 7.11 also has 3 significant digits, the answer would also contain 3 significant digits.
For 
Thus the solution to the problem expressed to he correct number of significant figures is 1.69
Substances have different tendencies to donate or accept electrons. When a really good donor meets a great acceptor, the chemical reaction releases a lot of energy. Oxygen (O2) is the best electron acceptor and is used in many aerobic reactions (reactions with oxygen). Hydrogen gas (H2) is a good electron donor.
When O2 and H2 are combined, along with a catalyst, water (H2O) is formed. This example of a redox reaction can be written like this:

33.6 moles are needed to completely react with 84.0 moles of O2
Answer:
2Na=Ca(OH)000.1 AgBr=2KF 2KBr=LiNO
Answer: scientific explanation
Explanation:
A really good scientific explanation should do two main things: It should explain all the observations and data we have. It should allow us to make testable predictions that we can check using future experiments.
