Atoms, ions and compounds

Question 1

Whats’s the mass of a proton

Answer 1

1

Question 2

What’s the mass of an electron

Answer 2

1/1836

Question 3

What’s the mass of neutron

Answer 3

slightly greater than a proton

Question 4

What’s the charge of a proton

Answer 4

equal to electron but opposite

relative charge of +1

Question 5

What’s the charge of a neutron

Answer 5

neutral no charge

Question 6

What’s the charge of an electron

Answer 6

equal to proton but opposite

relative charge of -1

Question 7

What the role of neutrons

Answer 7

as despite the electrostatic repulsion between protons they hold the nucleus together

Question 8

As the nucleus gets larger…

Answer 8

… more and more neutrons are required

Question 9

Isotope

Answer 9

atoms with the same element with the same number of protons but different numbers of neutrons and thus different masses

Question 10

Atomic number

Answer 10

the number of protons in the nucleus of an atom

Question 11

Mass number

Answer 11

the sum of the number of protons and neutrons present in the nucleus
ALSO KNOW AS NUCLEON NUMBER

Question 12

Proton number

Answer 12

the number of protons present in the nucleus

Question 13

Atomic number symbol

Answer 13

Z

Question 14

Mass number symbol

Answer 14

A

Question 15

Why do isotopes have similar chemical properties

Answer 15

they have the same number of electrons
the number of neutrons has no effect on an elements reactions as it doesn’t effect their electronic structure
THEREFORE different elements of isotopes react on the same way

Question 16

Why is it hard to CHEMICALLY distinguish isotopes

Answer 16

as they have the same electronic configuration and neutrons does not effect the elements reactions
THEREFORE
they have the same number of electrons in their outer shell so they from the same ions during a chemical reaction

Question 17

Why might isotopes have varying physical properties

Answer 17

as the increased mass may cause an increased
melting point
boiling point
density

Question 18

Cations

Answer 18

POSITIVE IONS

- atoms with fewer electrons than proton s they have an overall positive charge

Question 19

Anions

Answer 19

NEGAITVE IONS

- atoms with more electrons than protons they have an overall negative charge

Question 20

Ion

Answer 20

a charged atom

Question 21

Relative isotopic mass

Answer 21

is the mass of an isotope compared to 1/12 of the mass of a carbon 12 atom

Question 22

Relative atomic mass

Answer 22

is the average mass of an atom of an element compared to 1/12 of the mass of a carbon 12 atom

Question 23

What causes mass deflect

Answer 23

the strong nuclear forces holding together protons and neutrons comes at the expense of a loss of a fraction of their mass
-so the adding together the relative masses of protons neutrons and electrons a small amount of mass is lost e.g. MASS DEFLECT

Question 24

How do you calculate the mass of atoms if some is lost due to mass deflect?

Answer 24

use the mass of a carbon 12 atom as standers
-total mass of C12
= 12u
-1u= standard weight of a proton/ neutron

Question 25

What is the weighted mean mass of an atom

Answer 25

the relative atomic mass

Question 26

What does the weighted mean mass take into account

Answer 26

• the percentage abundance of each isotope

- the relative isotopic mass of each isotope

Question 27

How can you determine the percentage abundance of each isotope in a sample of elements

Answer 27

a mass spectromemter

Question 28

How does a mass spectrometer work

Answer 28

• a sample is placed in the mass spectrometer
• the sample is vaporised then ionised to form positive ions
• the positive ions are accelerated
• as the heavier ions are slower and more difficult to deflect the ions of each isotope are separated
• the ions are detected on a mass spectrum as a mass to charge ration m/z
• the greater the abundance of ions the greater the signal
• when an ion is + the ratio=RIM