Answer:
D, a gas produced durning photosynthesis (i think)
Explanation:
Just finished the final exam 
 
        
                    
             
        
        
        
 It contain oxygen atom calculated below
<span>6.35gC x 2.00gO/1.50gC
 = 8.47g O 
</span><span>  The law is that a sample of a pure substance is the same as any other sample of the pure substance no matter what the source is
</span>hope it helps
        
                    
             
        
        
        
Answer:
1. As temperature and pressure increases, density increases
Explanation:
The earth is composed of three main layers: Crust, Mantle and Core. The density or mass per unit volume of the earth's layers increases as one moves from the surface towards the interior of the earth known as the core. Also, there is an increase in pressure and temperature as depth increases. There are three main sources of heat in the earth's core: (1) conserved heat from when the planet formed and coalesced, (2) heat due to friction caused by denser core material sinking to the center of the planet, and (3) heat from the decay of radioactive elements.
The earth's core is composed almost entirely of the metals, iron and nickel. The core has an inner solid layer and a molten outer core. Iron and nickel are both very dense metals, so the core of the earth is very dense and the density increases with depth with the inner core being the most dense layer of the earth.
 
        
             
        
        
        
Answer:
C
Explanation:
Natural selection is when an animal with a better trait survives and reproduces.  C is the best answer.