The differences between the Alkali metals and the Transition metals.
`The differences between the Alkali metals and the Transition metals In this essay I will explain the differences between the alkaline metals of Group 1 (la) in the periodic table and the Transition elements of groups 3 to 12 (lllb - llb) I will explain the reactivity, density, melting point, electronic metals and the uses. I will also compare the differences between the two groups. What are the Alkali metals? The alkali metals are a group of six elements that are in-group 1 of the periodic table. They have low melting points are soft compared to other metals and are so reactive that they are always combined with other elements. They are powerful reducing agents this meaning that they are always willing to lose an atom to have a complete outer shell that makes the element stable. What are the Transition elements? These elements are elements that share the same electronic orbital structure; this means that they have similar chemical properties. These elements are defined as 31 elements that have atomic numbers that range from 21-30, 39-48 and 71-80 in the periodic table .The transition metals sometimes take on negative oxidation states. There properties are similar to other metals: there similarities include malleability, ductility, high conductivity of heat and a high conductivity of electricity. The elements act as reducing elements or otherwise "Donors of electrons"
Identifying an Ionic Compound. Objectives: To learn and test for metal ions and non-metal ions and then apply them to discover the identity of an unknown ionically bonded substance
Identifying an Ionic Compound- Introduction Ionic compounds are defined as being compounds where two or more ions (an atom or group of atoms with an overall electrical charge) are held next to each other by electrical attraction. One of the ions has a positive charge - called a "cation", and the other has a negative charge - called "anion". Cations are usually metal atoms and anions are either nonmetal or polyatomic ions (ions with more than one atom). Usually, when we have ionic compounds, they form large crystals that you can see with the naked eye. Table salt is one of this- if you look at a crystal of salt, you can see that it has in irregular cube shape. This is because salt likes to stack in little cube-shaped blocks. When forming salt, Na readily loses an electron and Cl readily gains an electrons so both can become stable. Heat is added in the reaction so Na burns brightly in CL gas and a white solid forms on the sides of the container. This solid is salt, or sodium chloride. When the chlorine atom gained an electron, the atoms arrange themselves in a lattice. The force of attraction between a cation and anion is a very strong bond called an "ionic bond". This is an electrostatic attraction. An ionic bond happens between a metal and a nonmetal. Properties of salts: 0. All ionic compounds form crystals. 0. Ionic compounds tend to have high melting and boiling
A discussion of Atoms.
Atoms There are 112 elements although elements 110-112 are as yet unnamed. These 112 elements are organized in the periodic table: The modern chemical symbols were introduced by Berzelius. Rows of elements are called "periods" and columns of elements are called "groups" (1A, 2A 3B etc.). There are three general classes of elements distinguished by their physical properties: the metals (generally shiny and conduct electricity), the non metals (not shiny, sometimes gasses at STP and poor conductors of electricity) and the metalloids (properties in between those of metals and non metals.). Some groups have special names: Group 1A: Alkali metals Group 2A: Alkali earth metals Groups 3B-2B: Transition metals Group 7A: Halogens Group 8A: Noble gases Many of the heavier elements are unstable - which means that the atoms of those elements break apart very quickly. Elements within a group share similar chemical properties. Other chemical and physical properties of the elements can be deduced from their position in the periodic table. The structure of the periodic table and thus their chemical and physical properties is directly related to their atomic structure. Atomic Weights Most elements can be found on earth (with the exception of those elements that too unstable and thus must be synthesized in the laboratory). Since all elements have isotopes then we must consider how
Covalent bonding
Covalent bonding is an intermolecular form of chemical bonding characterized by the sharing of one or more pairs of electrons between two components, producing a mutual attraction that holds the resultant molecule together. Atoms tend to share electrons in such a way that their outer electron shells are filled - this is referred to as electron configuration. Such bonds are always stronger than the intermolecular hydrogen bond and similar in strength to or stronger than the ionic bond. In contrast to the ionic and metallic bond, the covalent bond is directional, i.e. the bond angles have a great impact on the strength of the bond. Because of the directional character of the bond, covalently bound materials are more difficult to deform than metals. The cause of the directionality is the form of the s, p, d, and f orbitals. In organic chemistry, the directionality of the bonding is often described by hybrid orbitals. Covalent bonding most frequently occurs between atoms with similar electronegativities. For this reason, non-metals tend to engage in covalent bonding more readily since metals have access to metallic bonding, where the easily-removed electrons are more free to roam about. For non-metals, liberating an electron is more difficult, so sharing is the only option when confronted with another species of similar electronegativity. However, covalent bonding involving
Chemistry revision notes. Atomic Structure and Bonding, Electrolysis, Acids and Alkalis.
Atomic Structure and Bonding (F) Atoms, Molecules and Ions. AN ATOM is the smallest particle of an element. They cannot be split into smaller particles in chemical reactions. Iron is made of iron atoms (Fe). Sulphur is made of sulphur atoms (S) A MOLECULE is a small group of atoms joined together. The atoms may be the same (e.g. O2) or different (e.g. H2O). The chemical formula shows the number and type of atoms present. Non-metal compounds are made of molecules: Carbon dioxide contains CO2 molecules Methane (natural gas) contains CH4 molecules AN ION is an atom or group of atoms with an electrical charge (+ or -). Metal compounds such as sodium chloride or copper sulphate contain ions. Sodium chloride is made of Na+ and Cl- ions Magnesium Oxide is made of Mg2+ and O2- ions Note that metals form positive ions while non-metals form negative ions. A solid is represented by (s). e.g. H2O(s) is ice. A liquid is represented by (l) e.g. Fe(l) is molten iron. A gas is represented by (g) e.g. H2O(g) is steam. A solution in water is represented by (aq). Salt dissolved in water is NaCl(aq). You should remember that the common gases are diatomic (have 2 atoms in each molecule). These are Oxygen O2; Hydrogen H2; Nitrogen N2; and Chlorine Cl2. Elementary Particles Atoms are made up of smaller particles called protons, neutrons and electrons. The protons and neutrons
The Sub-atomic particles
Foundation Chemistry The Sub-atomic particles Atoms are made of three main particles: protons, neutrons and electrons. > The protons and neutrons form the nucleus, in the centre of the atom > Protons and neutrons are sometimes called nucleons, because they are found in the nucleus. > The electrons surround the nucleus Properties of the sub-atomic particles PROPERTY PROTON NEUTRON ELECTRON Mass/kg .673 x 10 -27 .675 x 10-27 0.911x 10-30 (very nearly 0) Charge/C (Coulombs) +1.602x10-19 0 -1.602 x10-19 Position In the nucleus In the nucleus Around the nucleus These numbers are extremely small. In practice we use relative masses and charges. Relative atomic mass, Ar The relative atomic mass of an element is the average mass of the naturally occurring isotopes of the element relative to the mass of an atom of 12C (one atom of carbon 12 is given a relative atomic mass of exactly 12) ATOMIC NUMBER, Z=NUMBER OF PROTONS=NUMBER OF ELECTRONS Relative Isotopic mass The relative isotopic mass is the mass of an isotope of an element relative to the mass of an atom of carbon 12 (one atom of carbon 12 is given a relative atomic mass of exactly 12) Relative Molecular Mass, Mr The relative molecular mass of a compound is the mass of a molecule of the compound relative to the mass of an atom of carbon 12 (one atom of carbon 12 is given a relative atomic mass of
Revision notes on elements, the periodic table and compounds.
ELEMENTS Definition: An element is the basic building block of matter that cannot be broken down further by chemical reaction (This definition was suggested by Robert Boyle). Element can be broken down ONLY by nuclear fission. So far 106 elements have been discovered. Water (H2O) is not an element - because it can be further broken down into 1 oxygen & 2 hydrogen atoms. Carbon dioxide (CO2) is not an element - because it can be further broken down into 1 carbon & 2 oxygen atoms. Atmospheric oxygen (O2) is not an element - because it can be further broken down into 2 oxygen atoms. Note: H2O.......... CO2....... NO2 - these are compounds Every element has: * A name (may vary in different language) - Name may be taken from their Latin name - Name may be taken after the scientist who invented them - Name may be taken after the place where they were found * A symbol (same all over the world) Element Chemical symbol Hydrogen H Calcium Ca Chlorine Cl Iron Fe (from Latin name ferrum) Lead Pb Sodium Na Helium He In Universe: Most abundant element in universe - H (hydrogen) & He (helium) Stars are made of H & He Earth's crust: Most abundant element in earth's crust - O (oxygen = 45%) & Si (silicon= 25%) Others: - Aluminium (Al) = 7% - Iron (Fe) = 5% - Sodium (Na) = 5% - Calcium (Ca) = 4% - Magnesium (Mg) = 3% - Nickel (Ni) = 3% - Potassium
The effect of Hydrocholric acid on the Rate of Reaction
The Effect of Hydrochloric Acid on the Rate of Reaction Aim: My aim is to see if there is any change in the rate of reaction if the concentration of the acid increases. Variables: The independent variable in the experiment is the concentration of the hydrochloric acid; the concentrations are 0.1, 0.2, 0.3, 0.4 and 0.5M. The dependent variable will be the rate of reaction of the acid. The control variable is the amount of the concentration, the temperature of the acid and the time that the zinc is inside the acid. Hypothesis: My prediction is that as the concentration of the acid increases the zinc will react more but not necessarily quicker. In order for any reaction to happen, the particles must first collide. If the concentration is higher, the chances of collision are greater, thus resulting in a greater rate of reaction. Method: First I filled five different test tubes with the five different concentrations of the acid. I measured all of them to 20cm3. Then I collected five different pieces of zinc, and then weighed them on a scale. I recorded these results for later use. I made sure the temperature of the acids was the same using thermometers. I placed each piece of zinc in a different concentration and started the stop watch. After forty-five minutes I removed each piece of zinc and dried them with tissue paper. I then measured them with the same scales I had
Chemistry Revision Notes on atomic structure, nuclear power and the periodic table
Chemistry Major Developments of the Atomic Model > About 400BC: Greek philosopher Democritus first suggested that all substances consisted of tiny indestructible particles called atoms. > 1808: An English chemist named John Dalton described his ideas about matter. Dalton's ideas were based on many scientific experiments and observations. Although some of these today are to a degree, incorrect, Dalton's developments formed the early settlements that led to the modern atomic theory. Dalton stated a number of ideas: * All matter is composed of atoms * Atoms cannot be made or destroyed * All atoms of the same element are identical * Different elements have different types of atoms * Chemical reactions occur when atoms are rearranged * Compounds are formed from atoms of the constituent elements. > 1897: English Scientist Sir J.J. Thomson explained that the atom contained negatively charged particles called electrons. He suggested that atoms were positively charged spheres with negatively charged electrons embedded in them like the fruit in a plum pudding. > 1911: Lord Rutherford proposed a nuclear model for the atom. In his model, the atom consisted of mostly space with a dense nucleus containing positively charged protons in the centre. Negatively charged electrons orbited the nucleus. Although Lord Rutherford's model of the atom was essentially the same as today's
Nanochemistry. Buckminsterfullerene is an allotrope of Carbon with a Formula of C60.
Nanochemistry: Buckminsterfullerene Buckminsterfullerene is an allotrope of Carbon with a Formula of C60. It was discovered in 1985 by scientist at the Universities of Sussex and Rice. It was discovered by Harold Kroto, James R. Heath, Sean O'Brian, Robin Curl and Richard Smalley. The group named it after Richard Buckminster-Fuller because the shape is that of a Geodesic Dome and he was a noted architect who favoured this shape and the scientists thought it suitable. The dome is one comprised of hexagons and Pentagons [see below] and many examples can be seen in botanical gardens (e.g Missouri and Montreal). Buckminsterfullerene was not discovered because people wanted to discover it: it was discovered purely by chance. Scientists were trying to understand about the absorption of interstellar dust and the theorised that they must have long chains of atoms. Further research with a molecular beam proved their theory right (to some extent), as there were not long chains, just one big ball - hence the nickname "Bucky balls". The other allotropes of carbon (diamond and graphite are giant molecular structures whilst Buckminsterfullerene is simple molecular. This means that the structures of diamond could go on forever whilst Buckminsterfullerene has a defined shape and the molecule has a maximum number of atoms [see above]. Buckminsterfullerene has a maximum of C70 whereas each
