7. Fig. 17.15 shows the air in a balloon. Carbon dioxide N N N N O C O O N N O O N N Ar :Fig. 17.15 Argon
a. How many molecules are there in the balloon? b. How many different types of molecule are there? c. How many atoms are there? d. How many different types of atom are there? e. Does this balloon contain an element, compound or mixture? f. Name the elements present in air. g. Name the compounds present in air.
8. Answer questions a.–g. for each of the models (1–4) shown in Fig. 17.16. H O H Water N N N N Nitrogen Oxygen O Ar
1 :Fig. 17.16
a. Which box(es) show a representation of an element? b. Which box(es) show a representation of a mixture? c. Which box(es) show a representation of a compound? d. Which box(es) show a representation of a pure substance? e. Which box(es) show a representation of an impure substance? f. Which box(es) show a representation of a substance made up only of atoms? g. Which box(es) show a representation of a substance made up of molecules?