Answer is (C) It lacks quality experiments.
Phrenology is the study of the brain by looking at the size and the shape of cranium i.e., the skull. The study relies on empirical evidences that someone intelligent will have a bigger brain or will have a larger skull than a average person. These evidences however have no biological proof as they were not examined by conducting experiments. The study also rejected unsupported claims that a person with a smaller brain or skull size can be intelligent. Hence such a study or phrenology is considered a pseudoscience.
chloroplast turns light energy into chemical energy
A. From the insects and bugs they eat
Answer:
Water has several very unique properties, like surface tension, cohesion, and adhesion because water is polar and every water molecule electrically attracts the neighboring water molecules.
Explanation:
Water is a universal solvent and has several unique properties like surface tension, adhesion, cohesion, high specific heat, etc.
In a water molecule, the oxygen atom's nucleus attracts electrons more strongly than the nuclei of hydrogen atoms. The negatively charged electrons are pulled toward the oxygen atom's nucleus and away from the hydrogen atom nuclei. As a result, a negative electrical charge occurs in the middle part of the water molecule near the oxygen atom and a positive charge near the other parts of the molecule (hydrogen atoms). This unequal distribution of electrical charge between different parts of the water molecule (polarity) makes it a polar molecule.
The positive part of one water molecule (hydrogen atoms) is attracted to the negative parts of neighboring water molecules and as a result, hydrogen bonds are formed between hydrogen and oxygen atoms of adjacent water molecules. These hydrogen bonds between molecules help hold water molecules together.
Answer:
Explanation:
The <em>vapor pressure lowering</em> is a colligative property and it follows Raoult's law.
The <em>vapor pressure lowering</em> of a solvent in a solution, ΔP, is equal to the mole fraction of the solute, Xsolute, multiplied by the vapor pressure of the pure solvent, P°.
ΔP and P⁰ are given:
<u>1. Mole fraction of solute</u>
Thus, you can calculate Xsolute:
<u>2. Moles of solute</u>
Now you can calculate the number of moles of water and the number of moles of solute.
- Number of moles of water = mass in grams / molar mass
- Number of moles of water = 1,250g/18.015 (g/mol) = 69.3866mol
- Xsolvent = 1 - Xsolute = 1 - 0.02513 = 0.97487
- Xsolvent = moles of solvent / moles of solution
- 0.97487 = 69.3866mol / moles of solution
- moles of solution = 71.1752mol
- moles of solute = moles of solution - moles of solvent = 71.1752mol - 69.3866mol = 1.7886mol
<u>3. Mass of urea</u>
Formula:
- Mass = number of moles × molar mass
- Mass = 1.7886 mol × 60.06 g/mol = 107.42 g
You must round to 3 significant figures: 107 g
