Answer:
That iron atom is oxidized. It loses two electrons.
Explanation:
Compare the formula of an iron atom and an iron(II) ion:
- Iron atom:
; - Iron(II) ion:
.
The superscript 
in the iron(II) ion is the only difference between the two formulas. This superscript indicates a charge of on each ion. Atoms and ions contain protons. In many cases, they also contain electrons. Each proton carries a positive charge of 
and each electron carries a charge of 
. Atoms are neutral for they contain an equal number of protons and electrons.
Protons are located at the center of atoms inside the nuclei. They cannot be gained or lost in chemical reactions. However, electrons are outside the nuclei and can be gained or lost. When an atom loses one or more electrons, it will carry more positive charge than negative charge. It will becomes a positive ion. Conversely, when an atom gains one or more electrons, it becomes a negative ion.
An iron atom will need to lose two electrons to become a positive iron(II) ion with a charge of on each ion. That is:
.
- Oxidation is Losing one or more electrons;
- Reduction is Gaining one or more electrons.
This definition can be written as the acronym OILRIG. (Khan Academy.)
In this case, each iron atom loses two electrons. Therefore the iron atoms here are oxidized.
Answer:
B 1.23 g/cc
Explanation:
For something to float on seawater, the density must be less than 1.03 g/mL. If the object sinks, the density is greater than 1.03 g/mL.
Let’s examine the answer choices. Keep in mind, the ice berg is mostly below the water level.
A. 0.88 g/cc
This is less than 1.03 g/cc, which would result in floating.
B. 1.23 g/cc
This is the best answer choice. The iceberg is mostly beneath the water, but some of it is exposed. The density is greater than 1.03 g/mL, but not so much greater that it would immediately sink.
C. 0.23 g/cc
This is less than 1.03 g/cc, which would produce floating.
D. 4.14 g/cc
This is much greater than 1.03 g/cc and the result would be sinking.
In a Lewis structure, formal charges can be assigned to each atom by treating each bond as if one-half of the electrons are assigned to each atom. ... Resonance occurs in cases where two or more Lewis structures with identical arrangements of atoms but different distributions of electrons can be written.
Endothermic reactions, on the other hand, absorb heat and/or light from their surroundings. For example, decomposition reactions are usually endothermic. In endothermic reactions, the products have more enthalpy than the reactants. Thus, an endothermic reaction is said to have a positive<span> enthalpy of reaction. This means that the energy required to break the bonds in the reactants is more than the energy released when new bonds form in the products; in other words, the reaction requires energy to proceed.</span>
