The definition of a gem is "a precious stone, cut and polished for jewelry. They are all minerals. Some highly desirable gemstones may not be suitable for jewelry, yet be very collectible, like sphene. Others, like those in the corundum family, are prized for color and hardness, like emeralds and diamonds. Further, some common minerals, when polished, make beautiful pieces. With all that said, i woukd go with rarer.
Answer:
d. why matter exists
Explanation:
The kind of questions that chemistry CANNOT answer is "why matter exists".
In Chemistry, question of how the properties, composition and structure of substances are is answered. Also, the transformations that these substances undergo, and the energy that they release or absorbe during the transformation processes are revealed in chemistry.
Chemistry can answer the question of what forms of matter exists but cannot answer why matter actually exists.
Burning alcohol for fuel has been used throughout history. There are some alcohols that are the best ones to use as fuels because of their nature and can be synthesized chemicaly or biologicaly. Except, some of those alcohol also has a bad effect when burned for fuel as it would cause serious negative chemical effects when exposed to the human body such as blindness or death. Therefore, the best answer would be False.
When you are making a cake "for example" you put all the ingrediants together.. thrn put it in the oven.. the combination that makes the cake look like that or that combines the ingrediants together is by chemical reaction.
First you just have to say hi then when the other person says hi you just talk abt something you both wanna talk abt
