CIE iGCSE Co-Ordinated Science C2.2 Atomic structure and the Periodic Table Exam Style Questions Paper 4
Question
(a) Complete the sentences about the structure of an atom.
An atom has a central nucleus containing ……………………… and ………………………
and a series of ……………………… of electrons surrounding the nucleus.
(b) The element oxygen exists as isotopes.
State what is meant by isotopes.
(c) Oxygen atoms join together with covalent bonds to form oxygen molecules, O$_{2}$.
Complete the dot‐and‐cross diagram to show the bonding in an oxygen molecule.
(d) Oxygen atoms bond with silicon atoms to form silicon(IV) oxide, SiO$_{2}$, which has a high melting point and is hard like diamond.
Describe the way the silicon and oxygen bond in the structure of silicon(IV) oxide.
▶️Answer/Explanation
Ans : 5(a) protons (and) neutrons
shells
one or two correct for 1 mark
three correct for 2 marks
;;
5(b) (idea of) atoms of the same / an element ;
which have the same proton / atomic number ;
but a different nucleon / mass number ;
5(c)
one mark for double bond between oxygen atoms
one mark for rest of structure correct
;;
5(d) any two from:
macromolecular / (giant) lattice ;
each oxygen atom bonds with 2 silicon atoms ;
each silicon atom bonds with 4 oxygen atoms ;
sharing of electrons / covalent bond ;