Answer:
Stone A
Explanation:
Measuring density is an easiest way to determine if two similar looking substances are same or not. Here also we need to perform the density test for each stone that is suspected to be fake diamond. We will calculate the density of each stone and compare it with the density of original diamond.
Density is calculated using the formula

It has been given in the question that both the substances have same volume of 0.15
.
Density of stone A =
= 3.47
or after rounding off we get 3.5 
Density of stone B =
= 2.8 
It is clear from the above calculation that the stone A has same density as the diamond but stone B lacks behind in density.
So, stone A could be the real diamond.
Answer:
When the solution (with phenolphthalein) changes to colorless
Explanation:
When titrating with HCl is common to add phenolphthalein as an acid-base indicator.
Phenolphthalein is pink or fucsia when added into a basic solution. On the other hand when it is in acid solutions, is colorless.
So, when titrating, the NaOH solution will be initialy pink due to the phenolphthalein and when reaching the equivalence point, that color will fade out into colorless. This is how you know you hace reached the equivalent point.
Caffeine that is C8H10N402 is molecule which made up of 4 different elements. apart from carbon the other element includes
element symbol
nitrogen N
oxygen O
hydrogen H
The number of atom present in caffeine molecule are as follows
Nitrogen=4 atoms
Oxygen=2 atoms
Hydrogen=10 atoms
Answer:
The entropy and the systems surrounding it tend to increase.
Aluminum is one of the main factors that reduce plant growth in acid soils. Although it is generally harmful to plants in soils with a neutral medium, the concentration of positive aluminum ions in acid soils increases and malfunctions in root and function growth.
Most acid soils are saturated with aluminum rather than hydrogen ions. Soil acidity is the result of hydrolysis of aluminum compounds. This principle (lime correction) to determine the degree of base saturation in the soil has become the basis of the methods used in soil testing laboratories to determine the lime requirements for soil. Application of lime to soil reduces the toxicity of aluminum to plants. Note This connector loads slowly.
Adaptation of wheat to allow aluminum to be carried out is due to the fact that aluminum releases organic compounds that in turn combine with harmful aluminum cations. It is believed that sorghum has the same endurance. The first genes found to withstand aluminum were found in wheat. Aluminum sulphide bearing has been found to be governed by an individual gene, such as in wheat. This is not the case in all plants.