Chapter 2 atoms,ions and compounds

Question 1

what are the two subatomic particles that make up the nucleus

Answer 1

• protons
• neutrons

Question 2

What is the subatomic particle that not included in the nucleus

Answer 2

• electron

Question 3

where are electrons found

Answer 3

• occupies a region outside the nucleus
• electrons are arranged around the nucleus in shells

Question 4

What is the mass of an electron

Answer 4

1/1836

Question 5

wha is the mass of a proton

Answer 5

1

Question 6

what is the mass of a neutron

Answer 6

1

Question 7

what is the charge of a proton

Answer 7

+1

Question 8

what is the charge on an electron

Answer 8

-1

Question 9

what is the charge on a neutron

Answer 9

0

Question 10

what is the overall charge of an atom and why

Answer 10

• zero - neutral
• total positive charge from protons is cancelled by total negative charge from electrons

Question 11

what is an isotope

Answer 11

• are atoms of the same element with different numbers of neutrons and different masses

Question 12

what is the atomic number

Answer 12

the number of protons

Question 13

what is the mass number

Answer 13

number of protons + number of neutrons

Question 14

Descibr the reactivity of isotope of elements

Answer 14

• different isotomes of the same element have same number of electrons
• the number of neutrons has not effect on reactions of an element
• different isotoped of an element therfore react in the same way
• small difference in physical properties are seen

Question 15

what is an ion

Answer 15

charge atom
number of electrons different from the number of protons

Question 16

What are positive ions

Answer 16

• atoms with fewer electrons than protons
• overall positive charge
• cations

Question 17

What are negative ions

Answer 17

• anions
• atoms with more electrons than protons
• overall negative charge

Question 18

what is carbon - 12 and why is it important

Answer 18

• mass of a carbon-12-isotope is defined by exactly 12 atomic mass units
• the standard mass for atomic mass is 1 u the mass of 1/12th of an atom of carbon - 12
• on this scale 1u approximatley mass of a proton or a neutron

Question 19

what is the relative isotopic mass

Answer 19

• mass of an isotope relative to 1/12th of the mass of an atom of carbon 12

Question 20

what is the relative atomic mass

Answer 20

• most element contain a mixture of isotopes each with a different isotopic mass
• relative atomic mass is the weighted mean mass of an atom of an element relative to 1/12th the mass of an atom of carbon 12

Question 21

What does the weighted mean mass takes account of

Answer 21

• percentage abundance of each isotope
• relative isotopic mass of each isotope

Question 22

How is the percentage abundances of isotopes in a sample of an element

Answer 22

found experimentally using a mass spectrometer

Question 23

Describe how does a mass spectrometer work

Answer 23

• sample placed in a mass spectrometer
• sample is vaporised and then ionised to form positive ions
• ions are accelerated heavier ions more more slowly and are more difficult to deflect than lighter ions so ions of each isotope are seperated
• ions are detected on a mass sepctrum as a massto charge ration each ion reaching the detector adds to the signal

Question 24

how do you calculate mass to charge ration

Answer 24

relative mass of ion/relative charge on ion