Unit 1, Section 1-Atomic structure

Question 1

relative atomic mass Ar

Answer 1

average mass of an atom of an element on a scale where Carbon 12 is exactly 12

Question 2

Relative isotopic mass

Answer 2

average mass of an atom of an isotope of an element on a scale where Carbon 12 is exactly 12

Question 3

Calculating Ar

Answer 3

sum of (isotopic mass x Percentages) / total percentage

Question 4

relative molecular mass Mr

Answer 4

average mass of a molecule on a scale where an atom of C 12 is exactly 12

Question 5

relative formula mass

Answer 5

average mass of a formula unit on a scale where an atom of Carbon 12 is exactly 12

Question 6

calculating relative formula mass

Answer 6

sum of the Ar’s of ions in an ionic compound

Question 7

calculating Mr

Answer 7

add up all the Ar of all the elements in the molecule