Moles 1 Flashcards
What is an isotope?
atoms which have the same number of protons (so the same element) but different number of neutrons
How is an isotope distinguished?
mass number / number of nucleons
What are nucleons?
the sum of the number of protons and the number of neutrons (mass no)
What determines chemical properties of elements?
the forces of attraction and repulsion between the charged particles
number of protons
arrangement of electrons
Do isostopes have simular chemical properties?
almost identical chemical and physical properties
What is the relative mass?
the mass of any atom/molecule/ion is a given number on a relative scale where one atom of an isotope carbon-12 is has a mass of exactly 12
What is a pure isotope?
all atomes of the element have the same atomic mass
what is the relative isotopic mass?
the mass of an atom of the isotope compared with 1/12 of the mass of an atom of carbon-12
What is the relative atomic mass (Ar)?
the weighted mean mass of an atom of an element compared with 1/12 of an atom of carbon-12
What is a mass spectrometer?
a device which makes it possible to measure the mass of an induvidual atom or molecule
counts the relative numbers of atoms
How does a mass spectrometer work?
converts atom/molecule into a positive ion by removing electrons
measures the motion of the ion when passed through an electric/magnetic feild
What is Avogrado’s constant?
the number of paticles in an atom of 1g of carbon-12
6.022 x 10-23
What is Avogrado’s number abbreviation?
Na
What is a mole?
the amount of a substance that contains 6.022 x10-23 particles
What is 1 mole equal to?
the Ar/Mr/molar mass
