Of the gases listed, nitrogen, oxygen, water vapor, carbon dioxide, methane, nitrous oxide, and ozone are extremely important to the health of the Earth's biosphere. The table indicates that nitrogen and oxygen are the main components of the atmosphere by volume.
so the answer is D. Nitrogen and oxygen
hope this helps!
 
        
             
        
        
        
Answer:
16.89g of PbBr2
Explanation:
First, let us calculate the number of mole of Pb(NO3)2. This is illustrated below:
Molarity of Pb(NO3)2 = 0.595M
Volume = 77mL = 77/1000 = 0.077L
Mole =?
Molarity = mole/Volume 
Mole = Molarity x Volume 
Mole of Pb(NO3)2 = 0.595x0.077
Mole of Pb(NO3)2 = 0.046mol 
Convert 0.046mol of Pb(NO3)2 to grams as shown below:
Molar Mass of Pb(NO3)2 =
207 + 2[ 14 + (16x3)] 
= 207 + 2[14 + 48] 
= 207 + 2[62] = 207 +124 = 331g/mol 
Mass of Pb(NO3)2 = number of mole x molar Mass = 0.046 x 331 = 15.23g
Molar Mass of PbBr2 = 207 + (2x80) = 207 + 160 = 367g/mol
Equation for the reaction is given below:
Pb(NO3)2 + CuBr2 —> PbBr2 + Cu(NO3)2
From the equation above, 
331g of Pb(NO3)2 precipitated 367g of PbBr2
Therefore, 15.23g of Pb(NO3)2 will precipitate = (15.23x367)/331 = 16.89g of PbBr2
 
        
             
        
        
        
The five main branches of chemistry are organic chemistry, inorganic chemistry, analytical chemistry, physical chemistry and biochemistry. Chemistry can be further divided into many sub-branches that may fall under more than one of the main branches.
        
             
        
        
        
Answer:

Explanation:
Density is found by dividing the mass by the volume. 

The mass of the liquid is 12.7 grams. 
We know that 15 mL of this liquid was added to a 50 mL graduated cylinder. Therefore, the volume is 15 mL. The 50 mL is not relevant, it only tells us about the graduated cylinder. 

Substitute the values into the formula.

Divide. 

Round to the nearest hundredth. The 6 in the tenth place tells us to round the 4 to a 5.

The density of the liquid is about 0.85 grams per milliliter and choice A is correct.