Answer:
See Explanation
Explanation:
An endothermic reaction is one in which energy is absorbed and the change in enthalpy for the reaction is positive.
If we look at the reaction 2HgO + 45kcal ----> 2Hg + O2; we will notice that
i) 45kcal of energy was taken in (absorbed) for the reaction to occur
ii) The value of the reaction enthalpy is positive
For these two reasons, the reaction is an endothermic reaction as written.
Answer:
Described by a redox reaction below
Explanation:
Iron(III) oxide is an ionic compound, since it consists of a metal, iron, and a nonmetal, oxygen.
Ionic compounds are formed when metals lose their valence electrons in order to have an octet in their previous shell and donate them to nonmetal atoms, so that nonmetals fill their outer shell to have an octet.
As a result, positive ions (cations) and negative ions (anions) are formed. When iron reacts with oxygen, the following reaction takes place:

This is a redox (oxidation–reduction) reaction, since we have electron loss and gain. Four iron atoms lose a total of 12 electrons to obtain a +3 charge in the final compound, while 3 oxygen molecules gain these 12 electrons to become 6 oxide anions with a -2 charge.
Answer:
John Dalton's Atomic Model Below ⬇
Explanation:
Answer:
16
Explanation:
4 nitrogen (N) atoms and 12 (3×4) atoms in Hydrogen (H)
Total = 4 + 12 = 16 molecules