2.1.1 Atomic Structure And Isotopes

Question 1

What charge is a proton?

Answer 1

+1

Question 2

What charge is a proton?

Answer 2

+1

Question 3

What charge is a neutron?

Answer 3

0 (neutral)

Question 4

What charge is an electron?

Answer 4

-1

Question 5

What is the mass of an electron?

Answer 5

1/1836

Question 6

What is the mass number?

Answer 6

Protons + Neutrons

Question 7

What is the atomic number?

Answer 7

Protons

Question 8

Where are protons found?

Answer 8

In the nucleus

Question 9

Where are neutrons found?

Answer 9

In the nucleus

Question 10

Where are electrons found?

Answer 10

Arranged around the nucleus in shells.

Question 11

What are isotopes?

Answer 11

Atoms of the same element with different number of neutrons and masses. (Same number of protons)

Question 12

What is an ion?

Answer 12

A charged atom, with different numbers of electrons and protons.

Question 13

What is relative atomic mass?

Answer 13

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

Question 14

What is relative isotopic mass?

Answer 14

The weighted mean mass of an isotope relative to 1/12th of the mass of a carbon-12 atom.

Question 15

How does a mass spectrometer work?

Answer 15

The sample is vapourised
The sample is ionised to form positive ions
The ions are accelerated
Heavy ions move slower / are less deflected
The ions are detected as a mass-to-charge ratio, written as m/z
Each ion produces a signal, so the larger the signal, the greater the abundance.

Question 16

How can relative atomic mass of an element and its isotopes be found?

Answer 16

Using a mass spectrometer . Percentage abundance × m/z

Question 17

Why can we assume m/z = mass , in mass spectrometry?

Answer 17

Most of the time, only one electron is lost in ionisation of the sample.

Question 18

What is the history of the atom?

Answer 18

John Dalton - spheres
Jj Thompson - plum pudding
Ernest Rutherford - gold leaf
Niels Bohr - fixed energy shells