Atomic structure

Question 1

What is the relative mass of a proton?

Answer 1

1

Question 2

What is the relative mass of a neutron?

Answer 2

1

Question 3

What is the relative mass of an electron?

Answer 3

1/2000

Question 4

What is the relative charge of a proton?

Answer 4

+1

Question 5

What is the relative charge of a neutron?

Answer 5

0

Question 6

What is the relative charge of an electron?

Answer 6

-1

Question 7

What is the top number on the periodic table?

Answer 7

Mass number

Question 8

What is the bottom number on the periodic table?

Answer 8

Atomic number

Question 9

What is the mass number?

Answer 9

Total number of protons and neutrons.

Question 10

What is the atomic number?

Answer 10

Number of protons (and therefore electrons).

Question 11

Do negative ions have more protons or electrons?

Answer 11

More electrons

Question 12

What is an isotope?

Answer 12

An atom with the same number of protons but different number of neutrons.

Question 13

Do isotopes have the same chemical properties?

Answer 13

Yes

Question 14

What affects chemical properties?

Answer 14

Configuration of electrons.

Question 15

What affects physical properties?

Answer 15

Mass

Question 16

Do isotopes have the same physical properties?

Answer 16

No

Question 17

What did John Dalton discover about the atom?

Answer 17

*atoms are spheres
*each element is made from different spheres

Question 18

What did J.J.Thompson discover about the atom?

Answer 18

*discovered electrons
*came up with the plum pudding model
*the atom isn’t solid

Question 19

What is the plum pudding model?

Answer 19

The atom is made up of a positive ‘pudding’ and negative ‘plum’ electrons.

Question 20

What did Ernest Rutherford discover about the atom?

Answer 20

*discovered small and positively charged nucleus
*atom is mainly empty space
*negative electron cloud

Question 21

Explain Rutherford’s gold leaf experiment.

Answer 21

*positive alpha particles fired at thin gold leaf
*most went through (mainly empty space)
*small amount were deflected back (hit small positive nucleus)

Question 22

What did Neils Bohr discover about the atom?

Answer 22

*electrons were in fixed shells

Question 23

What did Neils Bohr think was the problem with Rutherford’s atomic model?

Answer 23

The negative electron cloud would collapse into the positive nucleus.

Question 24

Describe Neils Bohr’s experiement.

Answer 24

*EM radiation was absorbed by electrons causing them to move between shells
*electrons emit this radiation when they move to lower energy levels

Question 25

What was the order of discoveries about the atom?

Answer 25

*John Dalton - 1803 *J.J.Thompson - 1897 *Ernest Rutherford - 1909 *Neils Bohr - 1913

Question 26

What is different now about the atomic structure to Bohr's model?

Answer 26

Not all electrons in the same shell have the same energy, therefore there are sub-shells.

Question 27

What are the four steps involved in time of flight mass spectrometry?

Answer 27

1. ionisation 2. acceleration 3. ion drift 4. detection

Question 28

What are the 2 ways of ionising a sample?

Answer 28

*electrospray ionisation *electron impact ionsiation

Question 29

Describe electrospray ionisation.

Answer 29

*sample is dissolved and pushed through nozzel at high pressure - turns into gas *high voltage is applied to sample - each particle gains a H+ ion

Question 30

Describe electron impact ionisation.

Answer 30

*sample is vaporised *electron gun fires high energy electrons at it *one electron is knocked off each particle - forming 1+ ions

Question 31

Describe acceleration in mass spectrometry.

Answer 31

Ions are accelerated by an electric field to give them all the same kinetic energy.

Question 32

Describe ion drift in mass spectrometry.

Answer 32

*ions enter a region with no electric field *lighter ions drift faster than heavy ones

Question 33

Describe detection in mass spectrometry.

Answer 33

*lighter ions reach the detector first *when charged particles hit the detector they produce an electrical current *mass spectrum is produced

Question 34

Define relative atomic mass.

Answer 34

The average mass of an atom of an element when measured on a scale on which the mass of C12 is exactly 12.

Question 35

What is the symbol for atomic mass?

Answer 35

Ar

Question 36

Define relative molecular mass.

Answer 36

The average mass of a molecule when measured on a scale on which the mass of C12 is exactly 12.

Question 37

Define relative isotopic mass.

Answer 37

The mass of an atom of an isotope of an element when measured on a scale on which the mass of C12 is exactly 12.