Phototropism, Gravitropism, Thigmotropism, <span>Hydrotropism and Heliotropism</span>
The right answer is polarity.
In chemistry, polarity is a characteristic describing the distribution of negative and positive charges in a dipole. The polarity of a bond or a molecule is due to the difference in electronegativity between the chemical elements that compose it, the differences in charge that it induces, and to their distribution in space. The more the charges are distributed asymmetrically, the more a bond or molecule will be polar, and conversely, if the charges are distributed in a completely symmetrical manner, it will be apolar, that is to say non-polar.
Polarity and its consequences (van der Waals forces, hydrogen bonding) affect a number of physical characteristics (surface tension, melting point, boiling point, solubility) or chemical (reactivity).
Many very common molecules are polar, such as sucrose, a common form of sugar. The sugars, in general, have many oxygen-hydrogen bonds (hydroxyl group -OH) and are generally very polar. Water is another example of a polar molecule, which allows polar molecules to be generally soluble in water. Two polar substances are very soluble between them as well as between two apolar molecules thanks to Van der Waals interactions.
<span>The control would be a plant grown without any fertilizer. This is called a negative control and is important in identifying the influence of the treatments on the tests. In this case, it would mean that the plant without fertilizer (control) is not expected to grow as large as in the other treatment. </span>
There are two hydrogen atoms in a molecule of water.
I would think that an unweathered rock would be jagged while a weathered rock would be smooth because of water/wind or what ever weathered it.
