Relative formula mass Flashcards
What is usually the same as an element’s mass number?
Its relative atomic mass Ar.
What is the smaller number next to an element in the periodic table?
The element’s atomic number (amount of protons it has).
What is the bigger number next to an element in the periodic table?
The element’s mass number/relative atomic mass.
What happens when an element has more than one stable isotope?
The relative atomic mass is an average value of all the different isotopes (taking into account how much there s of each isotope).
What is a relative formula mass Mr?
When you add all the relative atomic masses for each part of the compound together.
Where do you find the Ar of any element?
From the periodic table.
What is the relative formula mass of a substance in grams known as?
One mole of that substance.
What is one mole?
A substances relative formula mass in grams.
How do we find the number of moles?
Number of moles = Mass in g (of element or compound)
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Mr (of element or compound)
