Grade 9 Science Chemistry Exam Review 2014 | Page 16

48. ANS: The 2+ represents the loss of two electrons that occurred to make the atom stable (having a full outer valence shell). 49. ANS: 50. ANS: Elements are individual atoms (or atoms of the same type), whereas compounds are groups of different atoms joined together. PROBLEM 51. ANS: 16 | P a g e