Answer:
Crystalline solids have well-defined edges and faces, diffract x-rays, and tend to have sharp melting points.
In contrast, amorphous solids have irregular or curved surfaces, do not give well-resolved x-ray diffraction patterns, and melt over a wide range of temperatures.
Again great job! They all look correct except 20. is 3.7 due to sig fig of least precision, which you have a mark by!! You don't even need help!;) Here comes the next chemical engineer! :)
Answer:
Explanation:
Such types of compounds in which conjugated planer ring system and delocalized pi electrons are present are called aromatic compounds such as Toluene, Benzene and some other. Generally, these compounds follow Huckle's rule. The trisubstituted ring means a compound in which three hydrogen atoms are replaced by three other groups. In the given compound two hydrogen atoms are replaced by two methyl groups and one hydrogen atom is replaced by one Chlorine atom. From the given compound , and can be drawn.
To calculate atomic mass, you have to take to weighted average of the isotopes' masses. What that means is M = RA*106 + (1 – RA)*104, where RA is relative abundance expressed in decimal form. If you simplify the right side of that equation, you get M = 2*RA + 104. Doing a little more algebra yields RA = (M –104)/2 = (104.4 – 104)/2 = 0.4 / 2 = 0.2, which is 20%. So the answer is B.
