1.12 - Mass spectromerty and relative masses of atoms, isotopes and molecules

Question 1

What is relative atomic mass?

Answer 1

The mass of atoms, relative to each other

e.g. Sulfur = 32, Oxygen = 16, so a sulfur atom is twice as heavy as an oxygen atom

Question 2

What are the masses of atoms relative to?

Answer 2

The relative atomic mass of a hydrogen atom, which is 1

Question 3

What complicated this idea?

Answer 3

The discovery of isotopes

Question 4

After this complication, what was used as the standard for comparisons concerning relative atomic mass?

Answer 4

An isotope of carbon, carbon-12

Question 5

What 2 things are required to calculate the relative atomic mass of an element?

Answer 5

The relative isotopic masses and their percentage abundance in a sample

Question 6

What is a mass spectrometer?

Answer 6

A piece of apparatus that measures the masses of atoms and molecules

Question 7

Complete the sentence: A mass spectrometer produces _______ ____ that are deflected by a magnetic field according to their ____-to-______ ratio (m/z)

Answer 7

Positive Ions

Mass-to-charge

Question 8

What else does a mass spectrometer do?

Answer 8

It calculates the relative abundance of each positive ion and displays this as a percentage

Question 9

What 3 things could the positive ions be?

Answer 9

Positively charged atoms, positively charged molecules or positively charged fragments of molecules