Snape and Dumbledore both agree that safety must be a priority. Before we get into the more challenging questions they think we
should review some safety practices. For the reactivity of metals experiment which of the following is a laboratory safety precaution? Please read all the choices before choosing an answer.A) Since you will be working with hydrochloric acid (6M) care must be exercised not to get this acid on your clothes or skin. If you should come into physical contact with it, wash if off as fast as possible with copious amounts of water. Then inform your teaching assistant of your spill.B) You must wear goggles in this laboratory.C) Handle your thermometer with care. When you remove it from your drawer be sure to hold both ends of the thermometer so that it does not slip out.D) No flames of any type will be permitted in the laboratory while this experiment is being performed.
The correct answer is option C) "Handle your thermometer with care. When you remove it from your drawer be sure to hold both ends of the thermometer so that it does not slip out".
Explanation:
Handling a thermometer with care is part of the laboratory safety precautions that should be considered regarding to the reactivity of metals. Old thermometers are based on the element mercury, a shining metal that is the only element that is in liquid state on room temperature conditions. Mercury is very toxic, and is particularly dangerous because it vaporizes at room temperature and it could be inhaled.
<em>Fractional distillation leads to a better separation than simple distillation because the glass beads in the fractionating column provide "theoretical plates" on which the vapors can condense and then re-evaporate, and re-condense, essentially distilling the compound many times over.</em>
A leaf needs carbon dioxide and water for photosynthesis. ... For carbon dioxide to enter, the stomata on the surface of the leaf must be open. As you have seen, transpiration draws water from the roots into the leaf mesophyll.
The hydrogen molecules combine with the oxygen molecules, 2 hydrogen molecules, and 1 oxygen molecules is the amount needed to make one water atom or molecule, whatever you want to call it.
