Answer:
There are three significant figures
Explanation:
When counting sig figs you don't count the zeros unless it is between a number greater than zero. The two zeros aren't between the greater numbers so there are only 3.
 
        
             
        
        
        
Answer:
The organs present inside the chest are :
1. The lungs 
2. The heart
Explanation:
The chest cavity is also called as the thoracic cavity. It is the second largest hollow space of the body.In the bottom , it is enclosed by the diaphragm.
This cavity actually contain three space each round with mesothelium , pleural cavity and precardial cavity. 
This contain the lungs , the tracheobronchial tree , the heart , the blood vessels which transport the blood between the heart and the lungs.
It also contain the esophagus .
Esophagus is the path through which the food passes from the mouth to the stomach.
 
        
             
        
        
        
Answer:
10.8 days (3 sig.figs.)
Explanation:
All radioactive decay is 1st order decay defined by the expression A = A₀e^-kt 
which is solved for time of decay (t) => t = ln(A/A₀) / -k 
A = final weight = 1.0 gram
A₀ = initial weight = 16.0 grams
k = rate constant = 0.693/t(1/2) = 0.693/2.69 days = 0.258 days⁻¹
t = ln(1/16) / -0.258da⁻¹ = (-2.77/-0.258) days = 10.74646792 days (calculator) 
≅ 10 days (1 sig. fig. based on given 1 gram mass) 
 
        
             
        
        
        
Always. You never know what kind of chemical you’re dealing with and how powerful it is.