Wednesday, March 18, 2020

Fire in a Bottle Chemistry Demonstration

Fire in a Bottle Chemistry Demonstration This fire bottle is a quick and easy alternative to the Barking Dog chemistry demonstration. The bottle displays a bright blue (or other colors) light, plus it emits a woof or bark. Several websites call this project a bottle fire vortex or bottle fire  tornado, but the flame propagates as a wave down the bottle, without spinning. Of course, you could spin the bottle on a carousel or turntable. Fire Bottle Materials Glass bottleAlcohol, at least 70 percentLong-handled lighter Procedure Pour a small amount of fuel into the bottle. You want 1/2 cm to 1 cm of liquid in the bottom of the bottle.Cap the bottle or cover the top with your hand, whichever works.Shake the bottle.If you have fuel on the lip of the bottle, wipe it off or blow on the bottle to evaporate the fuel. Otherwise, there is a good chance the flame will be restricted to this small area of the bottle. It is not a concern; just reduces the quality of the display.Carefully light the vapor just inside the mouth of the bottle.The flame should go out on its own, but if it does not, simply cover the mouth of the bottle and suffocate the flame.Each run uses up the oxygen in the bottle, which the fire needs in order to burn. You will need to blow fresh air into the bottle. You can blow into the bottle or else use a straw or tube. You probably will not need to add more fuel. Just add air, cover and shake the bottle, uncap it, and ignite the vapor.If you like, add a flame colorant to the fuel (e.g., boric acid fo r a green flame). Simply sprinkle some of the colorants into the bottle. Most colorants are not consumed by the flame, so even if you get to a point where you wish to add more fuel, you will not need to add more colorant chemical. Notes on Materials Glass Bottle:  You can use just about any bottle you want, but do be sure it is glass. Plastic  will melt. Also, the shape of the bottle, especially its neck, affects the sound that will be produced. You may wish to experiment with different types of bottles. We have had good success with a glass cola bottle and a large cylindrical glass water bottle. If by some miracle you have a giant graduated cylinder, go for it.Alcohol:  You can use other liquid fuels, too. You want some water in the fuel so that it will stick to the sides of the glass. You can add  chemicals to color the flame, too. Some of these will dissolve better in pure alcohol, which you can dilute with water or mix with rubbing alcohol.Long Handled Lighter:  You could drop a match in the bottle, but then you will need to fish it out to repeat the project. A flame  will shoot out the top of the bottle, so dont use a short lighter. A candle is another good option. Safety Info This is fire. It can burn you. Perform this project under competent adult supervision. Do not set the fuel next to your glass container. Do not perform this project on a flammable surface or near flammable objects (e.g., do not lean into the bottle with long hair, do not light the bottle next to drapes, etc.). Do be prepared to put the fire out in case of an accident. Having said all that, this project works well indoors. Actually, we recommend you try it indoors because you will get the best effect in still air, with no wind. Disclaimer: Please be advised that the content provided by our website is for EDUCATIONAL PURPOSES ONLY. Fireworks and the chemicals contained within them are dangerous and should always be handled with care and used with common sense. By using this website you acknowledge that ThoughtCo., its parent About, Inc. (a/k/a Dotdash), and IAC/InterActive Corp. shall have no liability for any damages, injuries, or other legal matters caused by your use of fireworks or the knowledge or application of the information on this website. The providers of this content specifically do not condone using fireworks for disruptive, unsafe, illegal, or destructive purposes. You are responsible for following all applicable laws before using or applying the information provided on this website.

Monday, March 2, 2020

How to Conjugate Mener (to Lead) in French

How to Conjugate Mener (to Lead) in French The French verb  mener  means to lead. Its a simple word, but there is one little trick to learning its conjugations. A quick lesson will show you what that is so you can properly say I led or we will lead. Conjugations of the French Verb  Mener    Mener is a  stem-changing verb. It follows some rules that apply to most verbs that end in -e_er, such as  lever  (to lift). Essentially, the stem change appears in certain verb forms where the first  e  is changed to  Ãƒ ¨.  While it doesnt affect the pronunciation, the spelling does change, so pay attention to this. Other than that one simple change,  mener  is conjugated in a similar manner to regular -er  verbs, which is the most common pattern found in French. This is great news because, with each new one you learn, they become easier. To study these conjugations, begin by identifying the verb stem:   men-. Then, you will match the subject pronoun with the appropriate tense for your subject. For example, I am leading is je mà ¨ne and we will lead is nous mà ©nerons. Subject Present Future Imperfect je mne mnerai menais tu mnes mneras menais il mne mnera menait nous menons mnerons menions vous menez mnerez meniez ils mnent mneront menaient The Present Participle of  Mener   The present participle of mener  is menant. To form this, we simply added  -ant  to the stem. This is a verb, of course, but in some contexts, it can become an adjective, gerund, or noun as well. The Past Participle and Passà © Composà © Another way to express the past tense led is to use the  passà © composà ©. Its a simple construction that uses the  past participle  menà ©. You will also need to conjugate  avoir  (an auxiliary verb) to fit the subject pronoun. For example, I led is jai menà © while we led is nous avons menà ©. More Simple  Mener  Conjugations to Learn After you memorize all of those forms of  mener, think about adding a few more simple conjugations to your vocabulary. They can be quite useful at times. For instance, if you need to imply uncertainty to the action, use the subjunctive. When the action is dependent on something else, turn to the conditional. When reading French, it will improve your comprehension to be able to recognize the passà © simple and the imperfect subjunctive  as forms of  mener. Subject Subjunctive Conditional Pass Simple Imperfect Subjunctive je mne mnerais menai menasse tu mnes mnerais menas menasses il mne mnerait mena ment nous menions mnerions menmes menassions vous meniez mneriez mentes menassiez ils mnent mneraient menrent menassent For short sentences such as exclamations and demands, you can use the imperative verb form and bypass the subject pronoun. Instead of tu mà ¨ne, use mà ¨ne alone. Imperative (tu) mne (nous) menons (vous) menez