Group VII Elements - Halogens The Group VII elements are called HALOGENS. The name Halogen means "salt - former" and is based on the fact that the elements combine with most metals to form salts. (halides) ELEMENT ======= FLUORINE ======== CHLORINE BROMINE ======= IODINE ====== State at 20oC GAS --- GAS --- LIQUID ------ SOLID ----- Colour PALE
Introduction “AOX” is the abbreviation of the sum parameter for water soluble “adsorbable organic halogens” in which ‘A’ stands for adsorbable, ‘O’ for organic and ‘X’ for the halogens chlorine, bromine and iodine. After the introduction of the AOX in 1976, this parameter has been correctly used for “real” AOX constituents (DDT and its metabolites, PCBs, etc.); but also misused for non-adsorbable adsorbed OX-compounds, mostly high molecular organohalogens in plants and even to inorganic compounds
scientific knowledge and understanding: Halogenoalkanes are classified as either primary, secondary or tertiary. In primary halogenoalkanes the halogen atom is covalently bonded to a carbon atom which is bonded to one other carbon, to two other carbons in secondary and three others in tertiary. Apparatus for a reflux Increasing the size of the halogen atom in the halogenoalkane decreases the bond strength, increasing the reactivity of the molecule, as the bond is easier to break. BOND
Fluorine is a corrosive, pale yellow gas and is the smallest of the Halogen group but also the element with the highest electronegativity in the Periodic Table. With such a high electronegativity it makes fluorine the most reactive of all of the elements. The high electronegativity of fluorine is beneficial in several goods, for example; polymers, toothpastes, pesticides, cancer drugs, and antibiotics. Fluorochloro-hydrocarbons are widely used in air conditioners and refrigerators, and have been
the Periodic Table Reactivity of the group 7 elements - the halogens Ref: Saunders N. 2000, Creative Chemistry You have seen that the Group 1 alkali metal elements increase in reactivity as you go down the group. Sodium is less reactive than potassium, which is less reactive than rubidium (which you weren’t allowed to observe directly!) Today, you will use displacement reactions to work out the order of reactivity of the Group 17 halogen elements using Chlorine, Bromine and Iodine. Hypothesis:
water which contains dissolved silver nitrate. Halogenoalkanes are alkanes which have one or more hydrogen atoms replaced by halogen atoms such as fluorine(F), chlorine(Cl), bromine(Br) and iodine(I) which are the elements in group VII in periodic table. Halogenoalkanes have the general formula, RX, whereby R is an alkyl or substituted alkyl group and X is any of the halogen atom. Besides, halogenoalkanes can also be classified into three categories according to what is attached to the functional
Balance the following chemical equations and separate the coefficients by commas and a space respectively (put a 1 if the coefficient is assumed 1): 5.3 Types of Chemical Reactions 5.3.1 Combination reactions Combination reactions are when two separate species react together to produce a new more complex compound. In other words, two species combine to form a new compound. These reactions take the form of: X+Y →XY Combination Reaction Synthesis reaction - sodium chloride formation of sodium
a very disagreeable odor. It’s Element Symbol is Cl, atomic number is 17, and atomic mass is 35.453. Chlorine’s melting point is -101 C or 149.8 F. The boiling point is -34.05 C or -29.29 F, at one atmosphere pressure. Chlorine is a member of the halogen group. Chlorine was discovered by Swedish scientist Karl Wilhelm in 1784, but he first thought it was a compound, rather than an element. In 1810, Sir Humphrey Davy named it Chlorine, from the Greek word meaning "greenish-yellow". Chlorine is used
Electron affinity is the amount of energy absorbed or released when an electron is added to a neutral atom in its gaseous state. Hence, it is a trend that shows the likelihood of an element to gain an electron in its valence shell. In the periodic table, some elements make bonds only with a group of other elements due to their electron affinities. Iodine and neon are two non-metals that may seem similar, but they react differently in bonds due to their affinity for electrons. To mention, neon is
1. Describe the use of lime in agriculture. -- The term lime maintains many meanings. It can refer to powdered limestone (calcium carbonate), a type of “quicklime” scientifically named calcium carbonate that decomposes to make calcium oxide upon heating, and calcium hydroxide; all of which are often recalled as being synonyms to the word lime and are used so accordingly. All of these variations are used for the exact same purpose; they all raise the pH of the soil in order to increase any possible
to fluorine among the halogen elements. Chlorine is a nonmetal. It is estimated that 0.045% of the earth’s crust and 1.9% of sea water are chlorine. Chlorine combines with metals and nonmetals and organic materials to form hundreds of chlorine compounds. Chlorine is about 2.5 times as dense as air and moderately soluble in water, forming a pale yellowish green solution. Chlorine is so reactive that it never occurs free in nature. Chemical Properties Chlorine is in the halogen family, and like all
There has been much excitement about the latest science news in which a remote controlled airplane was flown using seawater fuel. The U.S. Navy created the fuel by taking carbon dioxide and hydrogen from seawater and combing them to create an organic compound called a hydrocarbon, which can be used for energy. I believe this is a really an amazing discovery since the earth has a lot of seawater to use as fuel. The oil, gas and coal we currently use as fuel will not last forever. The possible use
Metalloids on the other hand have properties of both nonmetals and metals and they are found between the border that differentiates metals and nonmetals. Then, we have the nonmetals, Halogens and The Noble gases. Moreover, The halogens are group 17 and all halogens have 7 electrons in the outer energy shell so they become very very active because they really want to gain an electron to have a full outer shell. Finally, we have the Noble gases which are found in group 18
Fire and thermal properties of PA 66 resin treated with poly-N- aniline- phenyl phosphamide as a flame retardant Wenyan Lyu ABSTRACT In this study, a halogen-free phosphorous–nitrogen synergistic flame retardant, poly-N-aniline-phenyl phosphamide (PDPPD), was synthesized. The Fourier transform Infrared spectroscopy, nuclear magnetic resonance spectroscopy, and elements analysis data confirmed the structure of PDPPD. The essential flame retardant of FR PA66 was polymerized with PA66 pre-polymer
This experiment sought to utilize melting point, boiling point, infrared (IR) spectroscopy, and the index of hydrogen deficiency (IHD) to identify the structures of two unknown compounds. To ensure the successful identification of the unknowns, the molecular formula for each compound was found first. What the molecular formula does is that it allows chemists to identify elements present in a compound as well as the quantity of each element. The issue with this is that there are various compounds
different numbers of electrons in each energy level are what cause different elements to behave differently. For instance the halogens, group 17, have seven valence electrons and varying PELs so they are inclined to react with other elements in order to fufill their desire of having a full valence shell. This quality of having seven valence electrons is specific to the halogens; the alkali metals, alkaline earth metals, transition metals, rare earth metals, metalloids and non-metals all behave differently
INTRODUCTION During restoration of an affected tooth, if any margins between the composite restoration and tooth of concern are open, micro-leakage can occur1. Micro-leakage is a phenomenon in dentistry resulting from imperfect bonding that allows the movement of bacteria and fluids between the restoration and tooth of interest2. When a composite restoration is placed and undergoes polymerization through curing, shrinkage occurs. Research has shown that the percent of gaps between composite restorations
Most salons need to use energy-efficiency lights. They should try to use LED lights instead of halogens, because it is less energy and last longer than halogens. It is very important to save electricity in your salon. When customers get their hair done with hot water, they are running up the electricity bill. You should mix it with a little cold water, the temperature between
Bromine and Chlorine are the only two halogens currently used in flame retardants, making brominated and chlorinated flame retardants. These two elements have similar properties and mostly act the same way; they stop or interfere with the chemical mechanism that leads to the formation of flammable