The Night that Changed My Life :: essays research papers

The Night that Changed My Life The night’s darkness blanketed the cabin and the landscape like a mother and her newly born child. The winter snow on the ground illuminated the moon’s light and made it very easy for seeing into the distance, but there was nothing to see; for miles and miles tall pines and rolling terrain contained nothing but Mother Nature. I lay silently in my bed and watched out my window the snow drifting methodically to the ground. The tall pines stood watching over the cabin and their shadows seemed to have a life of their own. The howling wind caused an occasional screech and moan of the old wooden door. I was alone in my cabin except for the wicked cold, which made me a number of times reach for my blanket as it nipped at my exposed body. I trembled and my teeth began to chatter as I read my newspaper by the candlelight. As I began reading I came across an article about an escaped madman from a Maine jail. I looked at the picture and for some reason I thought I knew the man, bu t in reality I knew I did not. I continued to read as I tried to pass time as I expected the arrival of my girlfriend, Michelle, who like myself, was looking for an escape from this harsh world. This isolated spot in Northern Maine had great privacy and seldom had visitors. I lay patiently awake and a wait a knocking on my door. Suddenly, without warning, the candle blew out and a chill came across my body that was indescribable. I quickly rose to my feet to relight the candle, but I soon realized that I was out of matches. I hesitated to move, I hesitated to breathe, but then there was a knocking on my door and my heart suddenly dropped into my stomach. BANG, BANG, BANG. I stood frozen in the middle of the room like a deer caught in a car’s headlights. I practically crawled to the door to see who it was. I prayed after each step that it was Michelle, but for some reason I knew it was not. I went to the door and stood silent, almost like I was waiting for that person on the other side to open the door before I did, but they didn’t. I searched for the handle in the darkness, but I need not to find it.

Physical and Chemical Properties Essay

Purpose: The Physical and Chemical Properties lab provides the opportunity to investigate the physical and chemical properties of pure chemical substances and analyze the experiment results. Procedure: In the beginning of the experiment, I filled two 24-well plates half way with the given chemicals and sucked up these chemicals into their labeled pipets for later use. Following this, I performed a number of steps on each of the four test tubes and recorded observations of the different substances including odor, color, reaction to heat, the effects on the red and blue litmus paper and HCI reactions. Observations: As most of the observations are noted on the table above, it is a fair assumption that all of these substances went through some sort of change whether it was a chemical or physical change except for Zinc. This may be because I had dropped my Zinc sample and had a tough time retrieving the contents but never the less; it had very little to no reaction to the tests. Also, regarding the boiling point and melting point of different substances; some had no reaction at all. Questions: Did you observer any chemical changes in this experiment? Yes, Litmus paper is an example of chemical solely and was effected by all the substances except for Zn. What evidence did you use to decide that something was a chemical change? Chemical compounds of the litmus paper reacted with the chemical compounds of the substance tested to create a new compound resulting in a change of color of the litmus paper. No evidence was visibly seen when MgO Mg(OH)2. Give at least two examples of chemical changes you observed. One example was the reaction on the litmus paper and the second example was Magnesium oxide’s change into Magnesium hydroxide when introduced to water. Classify the following properties of sodium metal as physical or chemical †¢ Silver metallic color: Physical †¢ Turns gray in air: Physical †¢ Melts at 98oC: Physical †¢ Reacts explosively with chlorine gas: Chemical Classify the following changes as physical or chemical †¢ Water freezes at 0oC: Physical †¢ Baking soda when combined with vinegar produces bubbles: Chemical †¢ Mothballs gradually disappear at room temperature: Physical †¢ Ice cubes in a freezer get smaller with time: Physical †¢ Baking soda loses mass as it is heated: Physical †¢ Tarnishing of silver: Chemical F. How would you show that dissolving table salt is a physical change? By boiling the water and using a distillation process to extract the pure salt. Once all water is retracted, you can see that the salt never went through a chemical change. Conclusions: By conducting this lab, it can be seen that physical and chemical changes are an everyday occurrence among many different substances. Using prepared lab techniques, we can make qualitative observations on the appearance, smell, and reactions of different substances. The Physical and Chemical Properties lab provides the opportunity to investigate the physical and chemical properties of pure chemical substances and analyze the experiment results within the guiding principles and techniques. By doing so, the following can be learned though the experiment: Chemical properties describe the tendencies of a substance to undergo chemical change and physical properties commonly used to characterize pure substances are color, odor, hardness, density, melting point, boiling point, and solubility in various solvents.

Candle Science Trick to Extinguish Fire with Carbon Dioxide

You know you can put out a candle flame by pouring water on it. In this science magic trick or demonstration, the candle will go out when you pour air onto it. Candle Science Magic Trick Materials A lit candleA transparent glass (so people can see what is inside the glass)Baking soda (sodium bicarbonate)Vinegar (weak acetic acid) Set up the Magic Trick In the glass, mix together a little baking soda and vinegar. You want roughly equal amounts of the chemicals, like 2 tablespoons each.Put your hand over the glass to keep the carbon dioxide from mixing too much with the outside air.Youre ready to blow out a candle. If you dont have a candle handy, you can cover the glass with plastic wrap to store the carbon dioxide. How to Blow Out the Candle with Chemistry Simply pour the gas from the glass onto the candle. Try to avoid splashing liquid on the flame, since its not exactly amazing when water puts out a fire. The flame will be extinguished by the invisible gas. Another way to perform this trick is to pour the gas that you just made into an empty glass and then pour the apparently empty glass over the candle flame. How the Candle Trick Works When you mix baking soda and vinegar together, you produce carbon dioxide. The carbon dioxide is heavier than air, so it will sit in the bottom of the glass. When you pour the gas from glass onto the candle, you are pouring out the carbon dioxide, which will sink and displace the (oxygen-containing) air surrounding the candle with carbon dioxide. This suffocates the flame and it goes out. Carbon dioxide gas from other sources works the same way, so you could also perform this candle trick using gas collected from the sublimation of dry ice (solid carbon dioxide). How Blowing Out a Candle Works When you blow out a candle, your breath contains more carbon dioxide than it did when you inhaled the air, but theres still oxygen that can support wax combustion. So, you may be wondering why the flame is extinguished. Its because a candle needs three things to sustain a flame: fuel, oxygen, and heat. The heat overcomes the energy needed for the combustion reaction reaction. If you take it away, the flame cant sustain itself. When you blow on a candle, you force the heat away from the wick. The wax drops below the temperature needed to support combustion and the flame goes out. However, there is still wax vapor around the wick. If you bring a lit match close to a recently extinguished candle, the flame will re-light itself.