2.1 The Nuclear Atom Flashcards
What does the nucleus consist of?
Nucleons (Neutrons + protons)
Electrons
Subatomic particles that exist in energy levels outside the nucleus
Charge of protons, electrons, neutrons
P: 1+
E: 1-
N: 0
Mass of protons, electrons and neutrons
P: 1 amu
E: 1/1837 amu
N: 1 amu
What does Z stand for in the element?
It is the atomic/proton number
What does A stand for in the element?
Mass/Nucleon number
Where is mass concentrated?
In the dense nucleus. Electrons have close to no mass
What is an isotope?
Atoms of the same element with the same proton number but a different neutron number
Example of an isotope
Hydrogen: Protium, deuterium and tritium
Properties of isotopes
- Many isotopes are radioactive
- Same chemical properties as elements
- Different physical properties
- Lower mass:charge ratio = more deflection
Why do isotopes have the same chemical properties as their elements?
It is because electron number is the same and electrons decide chemical properties
What device can be used to calculate relative atomic mass?
Mass spectrometers
How do you calculate relative atomic mass?
- Isotopic mass x % abundance (for each isotope)
2. Add all products and divide by 100
How do you calculate percentage abundance?
- If there are two elements, multiply:
- 1st element’s mass with x
- 2nd element’s mass with (100-x) and so on - Multiply given relative atomic mass by 100
- Equate the sum of Step 1 with Step 2 and calculate
What are the 5 steps mass spectrometers use to calculate Ar (not really required)?
- Vaporization
- Ionization
- Acceleration
- Deflection
- Detection
