EL   The Elements of Life

EL1 Synopsis

A study of elements, in the human body, the solar system and the universe. Main topics:

·         constituent elements of the body

·         case studies of important elements in the human body: iron and calcium

·         the development of the Periodic Table

·         occurrence and origin of the elements in the universe

·         elements in the solar system;

·         molecules in outer space and in living things.

 

EL2

Learning outcomes

Candidates should be able to:

 

(a)     describe protons, neutrons and electrons in terms of their mass and relative charge;

 

(b)     describe the structure of atoms in terms of protons, neutrons and electrons;

 

      (c) explain and use the terms: atomic number, mass number, isotope, Avogadro constant,

           relative isotopic mass, relative atomic mass, relative formula mass, relative molecular mass;

 

(d) describe the elementary principles underlying the operation of a mass spectrometer;

 

 

      (e) use data from a mass spectrometer to determine relative atomic mass and the relative

           abundance of isotopes;

 

 

      (f)

use the concept of amount of substance to perform calculations involving: masses of substances, empirical and molecular formulae, percentage composition.

 

 

     (g)       

outline the formation of elements in stars by nuclear fusion processes;

 

 

     (h)

explain the occurrence of absorption and emission atomic spectra;

 

 

 

      (i)   interpret the atomic emission spectrum of hydrogen in terms of changes in electronic energy levels;

 

      (j)   recall that the nuclei of some atoms are unstable, and that these atoms are radioactive;

 

      (k) recall the different properties of alpha, beta and gamma radiations;

 

(l)       use nuclear symbols to write equations for nuclear processes, both fusion and       radioactive decay;

 

(m)   explain the use of radioactive tracers;

 

(n)     recall that the Periodic Table lists elements in order of atomic (proton) number and     groups elements together according to their common properties;

 

(o)             understand the way that ideas behind the Periodic Table developed historically;

 

(p) relate the position of an element in the Periodic Table to its electron structure (in terms of electron shells) and vice versa;

 

(q) interpret periodic trends in the properties of elements, in terms of:

(i) melting point and boiling point,

(ii) electrical conductivity,

(iii) ionisation enthalpy;    

 

(r)      relate ease of ion formation to ionisation enthalpy;

 

(s)     write equations for the first and successive ionisation enthalpies of an element;

 

(t)      use given data to describe trends in a group of the Periodic Table and to make predictions concerning the properties of an element in the group

 

(u) write and interpret balanced chemical equations;

 

(v)             describe and compare the following properties of the elements Mg, Ca, Sr, Ba in Group 2:

(i) reactions of the elements with water,

(ii) acid-base character of the oxides and hydroxides,

(iii) thermal stability of the carbonates,

(iv) solubilities of hydroxides and carbonates;

 

(w) draw and use simple electron ”dot-cross‘ diagrams to show how atoms bond

      through   ionic, covalent and dative covalent bonds;

 

(x)     describe a simple model of metallic bonding;

 

(y)   use the electron pair repulsion principle to predict the shapes of simple molecules

       (such  as CH4, NH3, and ions (such as NH4+) with up to four outer pairs of electrons

      ( any combination of bonding pairs and lone pairs) (no treatment of hybridization

       or  molecular orbitals is expected)   

 

(z)  explain molecular shape in terms of bond angles.