Atomic Structure Flashcards
Define:
- Atom
- Molecule
- Element
- Compound
- Mixture
- Atom: the smallest particle that makes up all things.
- Compound: two or more different atoms bonded together.
- Mixture: two or more different atoms together but not joined.
- Molecule: two particles (same or different) bonded together.
- Element: only 1 type of atom; this definition is applied to things both bonded and not to itself.
What is the structure of an atom in terms of positions, relative masses and relative charges of sub-atomic particles?
Name of particle-where it is found-relative charge-relative mass
Proton - nucleus - +1 - 1
Neutron - nucleus - 0 - 1
Electron - shells - -1 - negligible (1/2000)
Define:
- Atomic number
- Mass number
- Isotopes
- Relative atomic mass (Ar)
- Atomic number: the number of protons = the number of electrons (atoms are neutral).
- Mass number: protons + neutrons.
- Isotopes: atoms of the same element that have the same number of protons but a different number of neutrons.
- Relative atomic mass (Ar): the average mass of all the atoms of that element compared to the mass of atoms of the carbon-12 element.
How do you calculate the Relative atomic mass of an element (Ar) from isotopic abundances?
(Mass of isotope x fraction of isotope) + (mass of isotope x fraction of isotope)
How are elements arranged in the periodic table:
- According to atomic number?
- In groups and period?
- Increasing atomic number.
- -Groups: number of electrons in the outer shell
- Periods: number of shells
Why don’t the noble gases (elements in group 0/8) readily react?
They have a full outer shell, rendering them very stable.
Why do elements in the same group in the periodic table have similar chemical properties?
They have similar electronic configurations (although they don’t have the same number of shells, they have the same number of electrons in the outer shell).
