The minerals that one might be examining if you place some hydrochloric acid on a sample and it fizzes are Calcite and Dolomite.
Calcite and dolomite are very similar minerals. Both have the same hardness, the same rhombohedral cleavage, and are found in identical geologic settings. The best way to tell one from the other is the acid test; A drop of 1 M HCl on calcite produces an instant , obvious Fizz; a drop on dolomite produces slow or no obvious bubbling. 
        
             
        
        
        
I think the family of Group 2 metals are most likely to form a 2+ion.
 
        
             
        
        
        
The bones of the same animal found out continents far away from each other
        
             
        
        
        
Answer:
The answer to the question is 
The pressure of carbon dioxide after equilibrium is reached the second time is 0.27 atm rounded to 2 significant digits
Explanation:
To solve the question, we note that the mole ratio of the constituent is proportional to their partial pressure
At the first trial the mixture contains 
3.6 atm CO
1.2 atm H₂O (g) 
Total pressure = 3.6+1.2= 4.8 atm 
which gives 
3.36 atm CO
0.96 atm H₂O (g)
0.24 atm H₂ (g)
That is 
CO+H₂O→CO(g)+H₂ (g) 
therefore the mixture contained 
0.24 atm CO₂ and the total pressure = 
3.36+0.96+0.24+0.24 = 4.8 atm
when an extra 1.8 atm of CO is added we get Increase in the mole fraction of CO we have one mole of CO produces one mole of H₂ 
At equilibrium we have 0.24*0.24/(3.36*0.96) = 0.017857
adding 1.8 atm CO gives 4.46 atm hence we have
  (0.24+x)(0.24+x)/(4.46-x)(0.96-x) = 0.017857
which gives x = 0.031 atm or x = -0.6183 atm
Dealing with only the positive values we have the pressure of carbon dioxide = 0.24+0.03 = 0.27 atm
 
        
             
        
        
        
Answer:
B
Explanation:
the group number is=valence electrons. element 1 is in group 1 element 18 is in group 8. 1<8