Periodic Table: * Mass Number = protons + neutrons in the nucleus * Atomic Number = number of protons in the nucleus * Number of neutrons = mass number – atomic number Example: Lithium (Li) * # of protons + # of neutrons = mass # * 3 + 4 = 6.9/ 7 * The atomic mass is the mean of all the isotopes of Lithium in nature; round the number * Isotopes of a specific element have a varying number of neutrons * The number
Premium Chemistry Acid PH
a process that is usually characterized by a chemical change in which the starting materials (reactants) are different from the products. Chemical reactions tend to involve the motion of electrons‚ leading to the formation and breaking of chemical bonds. There are several different types of chemical reactions and more than one way of classifying them. Here are some common reaction types. However‚ if you are asked to name the main 4‚ 5 or 6 types of chemical reactions‚ here is how they are categorized
Premium Chemical reaction Hydrogen Chemistry
CHEMISTRY REVISION GUIDE for IGCSE Coordinated Science This revision guide is designed to help you study for the chemistry part of the IGCSE Coordinated Science course. The guide contains everything that the syllabus says you need you need to know‚ and nothing extra. The material that is only covered in the supplementary part of the course (which can be ignored by core candidates) is highlighted in dashed boxes: Some very useful websites to help you further your understanding include: •http://www
Premium Oxygen Ammonia Oxide
Heat of Combustion Questions 1. When bonds are broken‚ energy is required. When bond are formed‚ energy is released. All combustion reactions are exothermic. Suggest a reason for this in terms of the bonds broken and bonds formed. The energy required to break the bonds is greater than the energy required to form. 2. Explain why the heat of combustion of alkanols increases as the length of the carbon chain increases. The heat of combustion of alkanol increases as the length of carbon chain
Premium Heat Thermodynamics Hydrogen
Student Number Mark / 39 Chemistry Preliminary Course Final Examination • 2006 General Instructions • • • • • • • Reading time – 5 minutes Working time – 45 minutes Write using black or blue pen Draw diagrams using pencil Board-approved calculators may be used A Data Sheet and a Periodic Table are provided Write your Student Number at the top of this page Total Marks – 39 Part A – 10 marks • Attempt Questions 1 – 10 • Allow about 10 minutes for this part Part B – 29 marks • Attempt
Free Chemical reaction Hydrogen Solubility
magnesium salt and hydrogen. For example: Mg + 2HCl Mg + H2SO4 MgCl2 + H2 MgSO4 + H2 I discovered from an A’ level text book (A-level Chemistry by Ramsden) that nitric acid doesn’t usually give hydrogen‚ but may do with magnesium if the acid is cold and dilute. The book didn’t say how dilute the acid had to be. Other products may include oxides of nitrogen. I know that some acids are weak and some are strong. A strong acid is one which ionises fully in solution to give hydrogen ions and‚ for example
Premium Hydrogen Sulfuric acid Acid
ways by which this reduction can occur. One is by a catalytic hydrogenation‚ this uses a catalyst such as palladium or nickel‚ hydrogen gas‚ and heat/pressure. This can reduced an alkane to alkene. This catalytic process is preferred in industrial practices because the cost is low in the long run and more importantly there is little to no waste expense. However‚ hydrogen gas is dangerous due to being very flammable/combustible. Therefore‚ a reducing agent will be used in this experiment instead.
Premium Hydrogen Alcohol
in each of the following molecules: O C NH2 H N O C OH H C CH2 (a) (b) O (c) Solutions: a. b. c. d. Amide‚ double bond Amine‚ carboxylic acid Double bond‚ ketone‚ ester O OCH3 (d) CH2OH Aromatic ring‚ double bond‚ alcohol (a) Alcohol (d) Amine (b) Aromatic ring (e) both ketone and amine (c) Carboxylic acid (f) two double bonds 3.2 Propose structures for simple molecules that contain the following functional groups: Solutions: (a). H 3C CH3 OH (b).
Premium Oxygen Hydrogen Functional group
INTRODUCTION Hydrocarbons are compounds that consists carbon and hydrogen only. They are the simplest organic compounds. Hydrocarbons‚ because of their number and variety‚ are classified into different ways. One way of classifying hydrocarbons is in which way carbon atoms are connected. It can be classified as either a chain aliphatic hydrocarbon or a cyclic hydrocarbon. Chain aliphatic hydrocarbons are compounds that are linked either in a single or branched chain. An example of this is hexane
Premium Hydrocarbon Carbon Petroleum
are large molecules that are formed from smaller molecules called monomers (Ellisman‚ 2014). They are formed by dehydration reactions‚ in which a water molecule is removed during the formation of bonds (Wayne Huang‚ 2015). Biological molecules are organic‚ indicating that they contain carbon and hydrogen atoms (Gair‚ 2013). The four classes of biological molecules are carbohydrates‚ proteins‚ nucleic acids and
Premium Protein DNA Oxygen