Answer:
The mass fraction of ferric oxide in the original sample :
Explanation:
Mass of the mixture = 3.110 g
Mass of 
Mass of 
After heating the mixture it allowed to react with hydrogen gas in which all the ferric oxide reacted to form metallic iron and water vapors where as aluminum oxide did not react.

Mass of mixture left after all the ferric oxide has reacted = 2.387 g
Mass of mixture left after all the ferric oxide has reacted = y

The mass fraction of ferric oxide in the original sample :

Answer: Energy of reactants = 30, Energy of products = 10
Exothermic
Activation energy for forward reaction is 10.
Explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and
for the reaction comes out to be negative.
Energy of reactants = 30
Energy of products = 10
Thus as energy of the product < energy of the reactant, the reaction is exothermic.
Activation energy
is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
for forward reaction is (40-30) = 10.
Answer:
Light energy; chemical
Explanation:
The light energy of the Sun is converted into chemical energy by the plants.
Answer:
Mantle
Explanation:
Convection currents in the Earth occur in the mantle. The core of the Earth is extremely hot, and material in the mantle close to the core is heated...
Hope that help <3
<span>Answer: B. Ionic solids have higher melting points than molecular solids.
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This is because the rest are false, as solids are able to melt, and do have melting points. Also, not all solids have the same melting points.