That friend is not correct. Physical change is characterized by a change in appearance without any change in composition. So, if the appearance did not change in the situation, then there is no change in the system. This type of change affects the form of a substance but not the composition or the structure of the molecules. Examples of this type of change are ice melting, cutting a paper into half, clay is molded to a new shape, butter melting, water evaporating. The change that involves a change in chemical composition is classified a chemical change. In this type of change, chemical reactions would take place.
Answer: both are solid at room temperture
Explanation:
Answer: 5/9 of the radius of the Earth. This is assuming that points are chosen randomly according to the following algorithm: We take a cube which precisely encloses the Earth and choose points uniformly from within that cube.
Explanation: YW . I hoped that helped.
Answer:
About 70% take at least 1 prescription medication and more than half take 2
To know if the solutions are isotonic, hypertonic or hypotonic, we have to determine the osmotic pressure of each solution.
P = iMRT
where
i is the number of ions dissociated for strong electrolytes
M is the molarity
R is the universal gas constant
T is the absolute temperature
For 0.15 M CaCl₂, i = 3 (1 for Ca⁺ and 2 for Cl⁻).
P = (3)(0.15)RT= 0.45RT
For 0.15 NaCl, i = 2 (1 for Na⁺ and 1 for Cl⁻).
P = 2(0.15)RT = 0.3RT
Therefore, the P for CaCl₂ is GREATER than the P for NaCl. <em>Hence, the CaCl₂ solution is hypertonic.</em>
