Atoms, bonding and moles Flashcards
What is an Element?
An element is a substance that only contains on type of atom.
What is the mass number of lithium?
[https://sciencenotes.org/hd-wallpaper-periodic-table/]
7
What is the Atomic number for Lithium?
[https://sciencenotes.org/hd-wallpaper-periodic-table/]
3
What is the mass number for Aluminium?
[https://sciencenotes.org/hd-wallpaper-periodic-table/]
27
What is the atomic number for Aluminium?
[https://sciencenotes.org/hd-wallpaper-periodic-table/]
13
What is the atomic mass equal to?
The number of protons
What is the mass number equal to?
The number of protons + neutrons
What is the number of protons equal to?
The number of electrons
How do you find out the number of electrons?
Its the same as the number of protons or the atomic number
How do you find the number of neutrons?
You do atomic number take away mass number
What is an isotope?
Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons, and therefore different mass numbers.
How do you calculate the relative atomic mass for an isotope?
You have to do:
(mass of isotope 1 X % of isotope 1) + (mass of isotope 2 x % of isotope)
/100
If (10)B has an isotopic abundance of 20% and (11)B has a n isotopic abundance of 80%, calculate the relative atomic mass:
You do (10 X 20) + (11 X 80) = 1080/100 = 10.8 /(20+80)
What is a compound?
Compounds are formed from elements in chemical reactions. A chemical change happens and at least one new product is formed. Elements are combined in fixed proportions and compounds can only be seperated by chemical means.
What is a mixture?
Mixtures are formed from elements or compounds combined by non-chemical means. The elements/compounds are unchanged, the elements/compounds in mixtures can be combined in any proportions and mixtures can be separated by physical means