Hi there,
the answer to the blank is: boiling point
When a liquid is heated, the temperature stops rising at the liquid's boiling point.
Hope this is correct :)
Have a great day 
 
        
                    
             
        
        
        
Answer:
B
Explanation:
By looking at how seismic waves change speeds as they travel
through Earth
 
        
                    
             
        
        
        
Answer:
Option D. 30 g
Explanation:
The balanced equation for the reaction is given below:
2Na + S —> Na₂S
Next, we shall determine the masses of Na and S that reacted from the balanced equation. This is can be obtained as:
Molar mass of Na = 23 g/mol
Mass of Na from the balanced equation = 2 × 23 = 46 g
Molar mass of S = 32 g/mol 
Mass of S from the balanced equation = 1 × 32 = 32 g
SUMMARY:
From the balanced equation above, 
46 g of Na reacted with 32 g of S. 
Finally, we shall determine the mass sulphur, S needed to react with 43 g of sodium, Na. This can be obtained as follow:
From the balanced equation above, 
46 g of Na reacted with 32 g of S.
Therefore, 43 g of Na will react with = (43 × 32)/46 = 30 g of S.
Thus, 30 g of S is needed for the reaction. 
 
        
             
        
        
        
12.0g x 1 mol / 63.546g = 0.188839581mol 
<span>So, for every 1 mole, we have 6.022 x 10^23 of whatever we're measuring. This gives us a conversion factor of (1 mole / 6.022 x 10^23 atoms) or (6.022 x 10^23 atoms / 1 mole).
</span>
0.188839581 mol x (6.022 x 10^23 atoms) / 1 mol = 1.137191955 x 10^23 
<span>Remember from before that we are limited to 3 significant figures. Since our calculations are complete, we can now round down to: 1.14 x 10^23 </span>
<span>That should be your answer!
Hope it helps!
xo</span>