Relative mass - 2.2 - (2)

Question 1

What do most elements contain a mixture of?

Answer 1

isotopes, each with a different relative isotopic mass

Question 2

What is relative atomic mass?

Answer 2

the weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon-12

Question 3

What does the weighted mean mass take account of?

Answer 3

the percentage abundance of each isotope and the relative isotopic mass of each isotope

Question 4

In the periodic table, in addition to the atomic number, each element is…

Answer 4

shown with its relative atomic mass

Question 5

How are percentage abundances of the isotopes in a sample of an element found?

Answer 5

using a mass spectrometer

Question 6

Are there different types of mass spectrometers?

Answer 6

yes

Question 7

Do all mass spectrometers work to the same basic principle?

Answer 7

yes

Question 8

Basic principle of mass spectrometers - 1) A sample is…

Answer 8

placed in the mass spectrometer

Question 9

Basic principle of mass spectrometers - 2)The sample is vaporised and then…

Answer 9

ionised to form positive ions

Question 10

Basic principle of mass spectrometers - 3) The ions are accelerated. Heaver ions move more…

Answer 10

slowly and are more difficult to deflect than lighter ions, so the ions of each isotope are separated

Question 11

Basic principle of mass spectrometers - 4) The ions are detected on a mass…

Answer 11

spectrum as a mass-to-charge ratio m/z.

Question 12

Basic principle of mass spectrometers - 4.1) Each ion reaching the detector adds to the…

Answer 12

signal so the greater the abundance, the larger the signal

Question 13

mass-to-charge ratio m/z =

Answer 13

relative mass of ion / relative charge on ion

Question 14

For an ion with one positive charge, what is this ratio equivalent to?

Answer 14

the relative isotopic mass, which is recorded on the x-axis of the spectrum

Question 15

What is the percentage abundance?

Answer 15

how much of that isotope we have

Question 16

What does m/z / mass to charge ratio mean?

Answer 16

tells us the different isotopes that have come through the mass spectra

Question 17

To calculate relative atomic mass - 1) Multiply them all, add them together and then…

Answer 17

divide them by 100 or total abundance

Question 18

To calculate relative atomic mass - Add up all abundances for…

Answer 18

total abundance

Question 19

To calculate relative atomic mass - After you get the answer after dividing by total abundance or 100, look at the…

Answer 19

periodic table to see which element it is