Answer:
You can see that it is an endothermic reaction or heat is being absorbed for the change from magnesium to magnesium oxide. So it is an endothermic reaction. So these are the four reasons why we can say that burning of magnesium ribbon in the air is considered a chemical change.
Explanation:
hope it help
Answer: electron on the shell of the atom
Explanation: that what I trying to remember
Answer:
By definition, there are 6.022×1023 such molecules, or NA such molecules in ONE mole of water. And thus in such a quantity there are NA oxygen atoms, and 2×NA hydrogen atoms...and the mass associated with this numerical quantity of water molecules is approx. 18⋅g ...
Answer:
a) 231.9 °C
b) 100% Sn
c) 327.5 °C
d) 100% Pb
Explanation:
This is a mixture of two solids with different fusion point:


<u>Given that Sn has a lower fusion temperature it will start to melt first at that temperature. </u>
So the first liquid phase forms at 231.9 °C and because Pb starts melting at a higher temperature, that phase's composition will be 100% Sn.
The mixture will be completely melted when you are a the higher melting temperature of all components (in this case Pb), so it will all in liquid phase at 327.5 °C.
At that temperature all Sn was already in liquid state and, therefore, the last solid's composition will be 100% Pb.
Answer:
The object will not float in water because the density of the object is greater than that of water.
Explanation:
Density of object = 1.75 g/mL
Density of water = 1 g/mL
The Density of the object is 1.75 g/mL and that of water is 1 g/mL. This implies that the object is denser (i.e heavier) than water. Therefore, the object will not float in water, rather it will sink in water since it's density is greater than that of water.