The Discarded Phlogiston Theory in Early Chemistry

The Discarded Phlogiston Theory in Early Chemistry Mankind may have learned how to make fire many thousands of years ago, but we didnt understand how it worked until much more recently. Many theories were proposed to try to explain why some materials burned, while others didnt, why fire gave off heat and light, and why burned material wasnt the same as the starting substance. Phlogiston theory was an early chemical theory to explain the process of oxidation, which is the reaction that occurs during combustion and rusting. The word phlogiston is an Ancient Greek term for burning up, which in turn derives from the Greek phlox, which means flame. Phlogiston theory was first proposed by the alchemist Johann Joachim (J.J.) Becher in 1667. The theory was stated more formally by Georg Ernst Stahl in 1773. Importance of Phlogiston Theory Although the theory has since been discarded, its important because it shows the transition between alchemists believing in the traditional elements of earth, air, fire, and water, and true chemists, who conducted experimentation that led to the identification of true chemical elements and their reactions. How Phlogiston Was Supposed to Work Basically, the way the theory worked was that all combustible matter contained a substance called phlogiston. When this matter was burned, the phlogiston was released.  Phlogiston had no odor, taste, color or mass. After the phlogiston was freed, the remaining matter was considered to be deflogistated, which made sense to the alchemists, because you couldnt burn them any more. The ash and residue left over from combustion was called the calx of the substance. The calx provided a clue to the error of phlogiston theory, because it weighed less than the original matter. If there was a substance called phlogiston, where had it gone? One explanation was the phlogiston might have negative mass. Louis-Bernard Guyton de Morveau proposed it was simply that phlogiston was lighter than air. Yet, according to Archimedes principle, even being lighter than air couldnt account for the mass change. In the 18th century, chemists did not believe there was an element called phlogiston. Joseph Priestly believed flammability might be related to hydrogen. While phlogiston theory didnt offer all the answers, it remained the principle theory of combustion until the 1780s, when Antoine-Laurent Lavoisier demonstrated mass was not truly lost during combustion. Lavoisier linked oxidation to oxygen, conducting numerous experiments which showed the element was always present. In the face of overwhelming empirical data, phlogiston theory was eventually replaced with true chemistry. By 1800, most scientists accepted oxygens role in combustion. Phlogisticated Air, Oxygen, and Nitrogen Today, we know that oxygen supports oxidation, which is why air helps to feed a fire. If you try to light a fire in a space lacking oxygen, youll have a rough time. The alchemists and early chemists noticed that fire burned in air, yet not in certain other gases. In a sealed contained, eventually a flame would burn out. However, their explanation wasnt quite right. The proposed phlogisticated air was a gas in phlogiston theory that was saturated with phlogiston. Because it was already saturated, phlogisticated air did not allow the release of phlogiston during combustion. What gas were they using that didnt support fire?  Phlogisticated air was later identified as the element nitrogen, which is the primary element in air, and no, it wont support oxidation.

How to Talk About Your Family in Italian

How to Talk About Your Family in Italian While Italians are passionate about a lot of things- food, calcio, fashion, to name a few- family is one of the most important. Since it is such an essential part of Italian culture, you’re  going to be asked about your family when you start to chat with natives, and it’s a great conversation starter. So what specific vocabulary words do you need to know, and which phrases will help the conversation flow smoothly? Basic Vocabulary - Family Members aunt la zia boy il ragazzo brother il fratello brotherinlaw il cognato cousin (female) la cugina cousin (male) il cugino daughter la figlia daughterinlaw la nuora family la famiglia father il padre fatherinlaw il suocero girl la ragazza grandchild il nipote granddaughter la nipote grandfather il nonno grandmother la nonna grandparents i nonni grandson il nipote husband il marito mother la madre motherinlaw la suocera nephew il nipote niece la nipote parents i genitori relative il parente sister la sorella sisterinlaw la cognata son il figlio soninlaw il genero stepfather il patrigno stepmother la matrigna step brother; half brother il fratellastro step sister; half sister la sorellastra uncle lo zio wife la moglie Conversational Phrases A casa tutto bene? - Is everything good at home?A casa here is used as in a figurative way to mean, â€Å"family†.​   Another option is to ask: Come sta la sua famiglia? - How is your family? If you want to ask informally, you can say, â€Å"Come sta la tua famiglia?† Come stanno i suoi? - How are your (parents)? If you want to ask informally, you can say, â€Å"Come stanno i tuoi?† FUN FACT: Italians shorten â€Å"i tuoi genitori† to â€Å"i tuoi†, so you can say â€Å"i miei† instead of â€Å"i miei genitori† and sound  more Italian. Ha fratelli o sorelle? - Do you have brothers or sisters? If you want to ask informally, you can say, â€Å"Hai fratelli o sorelle? Ha dei figli? - Do you have any kids? If you want to ask informally, you can say, â€Å"Hai dei figli?† Ho due maschi e una femmina. - I have two boys and one girl.Si chiama†¦ - His/her name is...Hai una famiglia numerosa! - You have a big family!Sono figlio unico. - I’m an only child. (male)Sono figlia unica. - I’m an only child. (female)Lei à ¨ sposato/a? - Are you married? If you want to ask informally, you can say, â€Å"Sei sposato/a?†. Use â€Å"sposato†, ending in -o, if you’re asking a male. Use â€Å"sposata,† ending in -a, if you’re asking a female. La mia famiglia viene dalla (Sardegna). - My family is from (Sardegna).Mio figlio si à ¨ appena laureato! - My son just graduated!Vado a trovare la mia famiglia (in Calabria). - I’m going to visit my family (in Calabria).Che lavoro fa (tuo marito)? - What does your husband do for work?Mia madre fa (l’insegnante). - My mother is a (teacher).Dove abita? - Where does he/she live?Le presento (mio marito). -   Let me introduce my husband to you. If you want to say this informally, you can say, â€Å"Ti presento (mia moglie)†. Mi saluti sua moglie! - Say hello to your wife for me! If you want to say this informally, you can say, â€Å"Salutami (tua moglie)!†. Practice Dialogue The best way to learn the language is to see the phrases and the vocabulary in action, so below you’ll find a practice dialogue between two friends who have run into each other on the street. Person 1: Ciao! Come stai? - Hey! How are you?Person 2: Sto bene, e tu? - I’m doing well, and you?Person 1: Tutto a posto, come sta la tua famiglia? - Everything is good, how is your family?Person 2: Sta bene, mia figlia si à ¨ appena laureata! - They are good, my daughter just graduated!Person 1: Complimenti!! E tuo marito? - Congratulations!! And your husband?Person 2: Lavora moltissimo, ma andr in pensione fra un anno. E tua figlia? - He’s working a lot, but he’ll be retiring in a year. And your daughter?Person 1: Giulia? La settimana scorsa ha compiuto sedici anni. - Giulia? Last week she turned 16 years old.Person 2: Davvero? Lei à ¨ cresciuta troppo in fretta! - Really? She grew up too fast!Person 1: Lo so, à ¨ cosà ¬. Allora, devo andare, à ¨ stato bello vederti, a presto! - I know, that’s how it is. Well, I’ve got to go, it was great to see, talk soon!Person 2: A presto! - Talk soon!