Atoms, Isotopes and Equations Flashcards
What are the three main subatomic particles in an atom?
Proton, Neutron and electron
Where is the proton found?
In the nucleus
What is the relative charge and mass of a proton?
Charge: 1+
Mass: 1
Where is a neutron found?
In the nucleus
What is the relative charge and mass of a neutron?
Charge: 0
Mass: 1
Where is an electron found?
In the energy levels/ shells around the nucleus
What is the relative charge and mass of an electron?
Charge: 1-
Mass: 1/1836
What is the definition for Atomic number (z)?
The number of protons in the nucleus and identifies an element
What is the definition for Mass number (A)?
Number of protons and neutrons in the nucleus
How can you calculate the number of neutrons?
N= mass number - atomic number
What is the number of electrons equal to?
The number of protons
What is the definition for an Ion?
Positively or negatively charged atoms/ group of atoms where the number of electrons is different from the number of protons
When is an ion formed?
When an atom gains or looses electrons
What is a cation?
A positive ion
What is a anion?
A negative ion
What is the definition for an isotope?
Atoms of the same element with the same number of protons and electrons, but different numbers of neutrons.
Why do isotopes have the same chemical properties?
Chemical reactions involves electrons, so isotopes of an element have the same chemical properties as they have the same number and arrangement of electrons.
What is the definition for relative mass?
As atoms are so small chemists use relative atomic masses to compare the masses of atoms, elements an compounds
What is the standard measurement of relative masses and why is it used?
Carbon-12, 12C is used as the standard measurement of relative masses, as 1/12th of 12C is essentially the mass of a proton/ neutron.
What is the definition for Relative isotopic mass?
Mass of an atom of an isotope relative to 1/12th of the mass of an atom of carbon-12
What is the definition for Relative atomic mass, Ar?
Weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon-12
What is a mass spectrometer used for?
A mass spectrometer can be used to identify isotopes and their abundances, which can then be used to calculate relative atomic mass
What are the 5 steps to mass spectrometry?
- The sample is VAPOURISED, then IONISED to cations.
- Ions are ACCELERATED to EQUAL KINETIC ENERGY so the heavier ions move more slowly towards the detector.
- Ions create a signal at the detector, the MORE ABUNDANT ions create a BIGGER signal.
- Lighter ions meet the detector first
- A computer converter turns the ELECTRICAL signals into a MASS SPECTRUM.
What is the equation for calculating Relative atomic mass from mass spectrometry?
Ar= Sum(Isotopic mass X abundance) / Total Abundance
