Atomic structure and Isotopes Flashcards
Foundations in chemistry
What is the mass of an electron?
1/1840
What is the mass of a proton?
1
What is the mass of a neutron?
1
What does the mass number tell you?
The protons and neutrons.
What does the atomic number tell you?
The number of protons.
What is an isotope?
Atoms of the same element having the same number of protons but a different number of neutrons.
What is relative isotopic mass?
The mass of an atom compared to one twelfth of the mass of an atom of carbon-12
What is the equation for relative isotopic mass?
mass of the atom of the isotope x12/ mass of atom carbon-12
Why are the atoms of noble gases stable and unreactive?
They have completely full outer shells.
What is Avogadro’s constant?
6.02x10²³
How do you find the moles of a substance?
Moles= mass/ molar mass
What is the empirical formula?
It gives the simplest whole number ratio of the number of atoms of each element present in the molecule.
What are the steps to working out the empirical formula?
- Divide both masses by the relative atomic mass.
- Write this as a ratio and simplify it.
- Write the formula.
What is the molecular formula?
It gives the actual number of each element present in the molecule.
