Answer:
The observation is an evidence of static electricity.
Explanation:
Static electricity refers to the stationary electric charge that is produced by friction. In other words, this kind of electricity is created when objects (2 objects for example) that are not good conductors of electricity are rubbed together.
During the rubbing process, electrons from the objects come in contact leading to the creation of a stationary electric charge. A good example of static electricity is when you are combing your hair and you see a spark in the mirror.
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 />
Answer:
Directly counting blood cells or tissue cells by using a hemocytometer can determine the concentration of a known volume. Counting the number of colonies that arise on a pour plate can calculate the concentration by multiplying the count by the volume spread on the pour plate.
At the smallest level of organization, the DNA wraps itself around small globular proteins called histones. Complexes of histones and DNA form nucleosomes, which appear as "beads" on the DNA strand. Chromatin refers to the decondensed DNA that has not formed separate chromosomes.
