Nails are made of iron because, iron is strong and sturdy; although nail rust when it undergoes oxidation when expose to water but it is not explosive.
Barium and phosphorus are not suitable for nail making because of their properties.
Barium is an element which reacts with virtually all non metals, forming poisonous products which are dangerous to health and to the environment. It also reacts explosively with water.
Phosphorus is not found in its pure form in nature, it conducts electricity and it is combustible in nature.<span />
The Sun's outer gases extend far beyond the photosphere (Figure 6). Because they are transparent to most visible radiation and emit only a small amount of light, these outer layers are difficult to observe. The region of the Sun's atmosphere that lies immediately above the photosphere is called the chromosphere.
The flow of energy is always one way. If we start at the sun and the sun’s energy moves to a plant, then the plant cannot transfer that energy back into the sun. The flow of energy is always controlled bc there is always a visible path it takes.
Answer:
Eukaryotes are organisms made out of eukaryotic cells, cells with a membrane-bound nucleus and membrane-bound organelles.
Prokaryotes differ from eukaryotes in that their cells do not contain a membrane-bound nucleus that contains their DNA.
Explanation:
TritionalshiftsofEscherichiacoliB/rtorichermediahavebeenanalyzedinsynchronouslygrowingandexponential-phasepopulations.Earlyperturbationsinthetimingofcelldivisionwereobserved.Attheslowgrowth,divisionpro-gressedatarateequaltoorlessthanthepreshiftrateforabout1h.Atintermediategrowth,bothdelaysandaccelerationindivisionwereobserved.Theextentoftheperturbationdependedupontheageofthecellsatthetimeoftheshiftandthecompositionofthepreshiftandpostshiftmedia.TheperturbationwasdifferentinthetwosubstrainsofE.coliB/r I got this from http://jb.asm.org/content/136/2/631.full.pdf hopefully it helps you