Q1: Gases diffuse easily through amorphous or porous solids.
Q2:All changes in phase are called change in state of matter.
Answer:
Explanation:
Gases diffuse easily through amorphous or porous solids. Usually solids are densely packed with no space. But porous solids can help in diffuse gas into them. Due to the vacancy present in these solids, gas can easily diffuse through these types of solids.
Similarly, the phase changes lead to change in the state of matter. As the basic of change in phase leads to change in its state from solid to liquid or from liquid to gas or vice versa. So change in state of matter will occur in any change in phase.
Very bad written question
C, then, D, A
The symbol used to indicate a substance is (aq).
When you focus on something
Answer:
See the image 1
Explanation:
If you look carefully at the progress of the SN2 reaction, you will realize something very important about the outcome. The nucleophile, being an electron-rich species, must attack the electrophilic carbon from the back side relative to the location of the leaving group. Approach from the front side simply doesn't work: the leaving group - which is also an electron-rich group - blocks the way. (see image 2)
The result of this backside attack is that the stereochemical configuration at the central carbon inverts as the reaction proceeds. In a sense, the molecule is turned inside out. At the transition state, the electrophilic carbon and the three 'R' substituents all lie on the same plane. (see image 3)
What this means is that SN2 reactions whether enzyme catalyzed or not, are inherently stereoselective: when the substitution takes place at a stereocenter, we can confidently predict the stereochemical configuration of the product.