Structure 1.2 The nuclear atom

Question 1

What is a nucleon?

Answer 1

Any particle in the nucleus

Question 2

How many natural elements are there?

Answer 2

92

Question 3

What is the effect of a changing mass (i.e. isotopes) on chemical properties?

Answer 3

Not much. Similar b/c same electron configuration

Question 4

What is the effect of a changing mass (i.e. isotopes) on physical properties?

Answer 4

Slightly different physical properties.
Lighter isotope will have lower density, greater diffusion + lower melting/boiling points

Question 5

What is a radioisotope?

Answer 5

An unstable isotope that breaks down spontaneously via radioactive decay (emitting nuclear radiation)

Question 6

What is a cation?

Answer 6

Positively charged ion (atom that has lost electrons)

Question 7

What is an anion?

Answer 7

Negatively charged ion (atom that has gained electrons)

Question 8

What is the relative isotopic mass?

Answer 8

The mass of an isotope relative to 1/12 the mass of a carbon-12 atom (ie. ~ 1 carbon-12 nucleon)

Question 9

What is mass spectrometry?

Answer 9

analytical technique that is used to measure the mass-to-charge ratio of ions

Question 10

How does mass spectrometry work?

Answer 10

A sample of an element is injected into the mass spectrometer.
Several electron streams hit the element, causing ioinsation. Result is isotopes with a charge (usually of 1+). These isotopes are accelerated by an electric field, until they reach an applied magnetic field. The magnetic field separates ions by weight and charge, with the lower mass-to-charge ratio being deflect more. The detection area measures the proportion of each isotope that hits the detection (seeing abundance)

Question 11

What does a mass spectrometer provide information about?

Answer 11

Number of isotopes in a given sample of an element
Relative isotopic mass of each isotope
Relative abundance of each isotope

Question 12

What does it mean if an isotope is abundant (usually)?

Answer 12

Usually more stable

Question 13

What is relative atomic mass?

Answer 13

weighted average of isotopic mass, according to relative abundances, relative to 1/12 of carbon-12

Question 14

What is the formula for Ar (relative atomic mass)?

Answer 14

(Ir(1) x %abundance + Ir(2) x %abundance + …) / 100

Question 15

What is metal dissolved in before being injected into the mass spectrometer?

Answer 15

Suitable acid mix