Pure water may be identified by its density: it will have the lowwest density of the three solutions, given that the solutes (salt and sugar) increase the density (this is the easiests and quickest way).
You can also measure the freezing points or boling points to identify the pure water because the solutes depress the freezing points and increase the boling points.
To differentiate sugar water and salt water, you can probe which one conducts electricity, because salt water is a conductor (given that it ionizes into Na+ and Cl-) but sugar water is not a conductor.
Hydrogen bonds are typically stronger than Van der Waals forces bc they are based on permanent dipoles, that form when hydrogen comes in vicinity of a highly electronegative atom (like F, N, or O). These bonds are long-lasting and pretty strong.
Billions of years ago, according to the theory of evolution, chemicals randomly organized themselves into a self-replicating molecule. This spark of life was the seed of every living thing we see today (as well as those we no longer see, like dinosaurs). That simplest life form, through the processes of mutation and natural selection, has been shaped into every living species on the planet.
Answer:
<em>The correct option is B) a gradual change of the traits of a species over time</em>
Explanation:
The theory of natural selection explains the gradual changes which occur in the population of a species over time. According to natural selection, those organisms which are better adapted to live in an environment survive and pass on their traits to their offsprings. As a result, the traits of a species tend to change over time through the process of evolution. Evolutionary changes do not occur rapidly, instead, they can take many years to occur.
If the cube is 3 cm on each side, then it has a volume of 27 cm^3 (3 x 3 x 3). Density is mass divided by volume, so its density is 72.9/27 = 2.7 g/cm^3.
<span>Going by the density, the cube is made of Aluminium - density is a fairly unique quantity</span>
