discrete groupings. Chemist use bonding types‚ electrical conductivity‚ melting and boiling point and physical properties to classify substances into four main groups‚ which are: • Metallic substances • Ionic compounds • Covalent molecular and; • Covalent network substances Metallic substances are substances that are made up of one or more metal. They have regular 3D lattice of positively charged ions. Metallic substances are bond together by metallic bond which has strong electrostatic
Premium Electron Atom Electric charge
between the t2g and eg orbital’s‚ also it can be seen in all terminated surfaces that both the majority and minority are metallic. When the depth increases the majority states are still metallic and have no distinct change at the Fermi level‚ while the minority states of each atom decrease relative to those of the atoms in the surface. For the Co-Co surface is lost the half–metallic (HM) properties of the bulk system with the spin polarization about –42%. The total density of states (DOS) as well as
Premium Chemistry Carbon Oxygen
Are determined by using the “magic number” (1.67) * Have bond angle and bond axis Characteristics of metallic bonds: * In metals (d-block electrons only..because of shape and prop.) * They’re delocalized (no electron ‘belongs’ to any one atom) * Known as the “sea of elements” because they’re floating around * Atomic radius determines how close atoms can get Hydrogen bonding: * Dipole-Dipole attraction * Occurs between H atoms (positive charge) and highly electronegative
Free Atom Electron Covalent bond
IB Chemistry Summary- By Paul Li & Silvia Riggioni TABLE OF CONTENTS Table of Contents............................................................................................................................................................ 1 Atomic Theory................................................................................................................................................................ 3 The Electromagnetic Spectrum.............................................
Free Atom Periodic table Covalent bond
Edexel IGCSE Chemistry Revision Notes IGCSE Chemistry Triple Award Revision Guide Topic Introduction to chemistry Atomic Structure Structure and Bonding – Ionic Bonding Structure and Bonding – Covalent and Metallic Bonding Organic Chemistry - Alkanes Organic Chemistry – Alkenes / Addition Polymerisation Organic Chemistry – Alcohols / Condensation Polymerisation Calculations Periodic Table Reactivity Series and Metal Extraction Electrolysis Energetics Acids‚ Bases‚ Salts and Neutralisation
Premium Atom Covalent bond Chemical bond
of the periodic table in terms of periods (1 – 7 )‚ Groups (1 – 18)‚ and metals/non-metals * Describe the trends in atomic size and down a Group and across a Period. * Describe the trend in MP across period 3. | Atomic structure and bonding I can | | | Atomic structure * State that matter is built up from minute particles called atoms. * Write the symbols and names of the following elements:
Premium Atom Chemistry Electron
appear across the period three oxides. Conductivity of electricity of molten oxide is likely to occur in the metal oxides as they have giant metallic structures which are capable of transferring delocalized electrons throughout their structure. This is not true of giant covalent structures and covalent bonds where all of their electrons are concerned with bonding‚ and therefore conductivity will not be a trait of non-metal elements in period three. Another expected trend across the period is that
Free Oxygen Oxide Chlorine
oxide e.g. 4Na (S) + O2 (g) → Na2O (s) Reaction with hydrogen element + hydrogen → hydride e.g. Ca (s) + H2 (g) → CaH2 (s) Reaction between an oxide and water metallic oxide + water → hydroxide * metallic oxide is also known as “basic oxide” e.g. Na2O (s) + H2O (l) → 2NaOH (aq) non-metallic oxide + water → acid * non-metallic oxide is known as “acidic oxide” e.g. SO2 (g) + H2O (l) → H2SO3 (aq) Reaction between active metals and water active metal + water (liquid or gas) → hydroxide
Premium Oxygen Nitrogen Carbon dioxide
Trends in Ionization Energy Period trends All the atoms in the same period have the same valence energy level and the same shielding. The increasing nuclear charge increases the attraction of valence electrons so ionization energy generally increases from left to right. The exceptions at full and ½ filled orbitals break the pattern because removing an electron from a stable (low energy) configuration will require more energy. Li has a low 1st ionization because 2 core electrons block the +3 nuclear
Free Periodic table Atom Electron configuration
Chapter 4 – Chemical Bonding: The Ionic Bond Model Study Questions Each question is worth 0.2 points. Total assignment is worth 5 points. 1. Describe the characteristics of ionic compounds and of molecular compounds. Ionic compounds have high melting points and conduct electricity well while covalent molecules have lower melting points and will not conduct electricity in a liquid state. 2. What types of particles are present as ionic bonds? Molecular compounds? Ionic bonding occurs between
Free Atom Electron Covalent bond