Atomic structure and the periodic table
Exam Questions and Answers
What is the relative mass of protons, neutrons and electrons? -
Answer>>Protons: 1
Neutrons: 1
Electrons: 1/1840
What is the relative charge of protons, neutrons and electrons? -
Answer>>Protons: +1
Neutrons: 0
Electrons: -1
What is atomic number? - Answer>>-The number of protons in
the nucleus of an atom of an element.
-All atoms of the same element have the same number of
protons.
What is the mass number? - Answer>>The total number of
protons and neutrons in the nucleus of an atom of an element.
What is an isotope? - Answer>>- Atoms of an element with the
same number of protons but a different number of neutrons.
- Same proton number but different mass number.
What affects the physical properties of an isotope? - Answer>>-
Mass of atom affects physical properties, so isotopes will have
slightly different physical properties e.g. different densities, rates
of diffusion.
What affects the chemical properties of an isotope? -
Answer>>-Number and arrangement of electrons determine the
, chemical properties, so isotopes have the same chemical
properties.
What is the relative atomic mass? - Answer>>- Ar, is the
AVERAGE mass of an atom of an element relative to 1/12th of
the mass of an atom of carbon-12.
- not usually a whole number.
What is the relative isotopic mass? - Answer>>- The mass of an
atom of an isotope, compared to 1/12th of the mass of an atom of
carbon-12.
- usually a whole number.
What is the relative molecular mass? - Answer>>- Average
mass of a molecule compared to 1/12th of the mass of an atom of
carbon-12.
What is the relative formula mass? - Answer>>- Average mass
of a formula unit compared to 1/12th of the mass of an atom of
carbon-12.
Difference between RMM and RFM? - Answer>>RMM: used
when referring to simple molecules. Find RMM by adding the
RAM of all the atoms in the molecule.
RFM: used for ionic compounds (or giant covalent e.g SiO2).
To find RFM, add up RAM of all the ions or atoms in the formula.
How to calculate relative atomic masses from isotopic
abundances? - Answer>>1. Multiply the relative isotopic mass
by its % relative isotopic abundance.
2. Add the products together.
Divide by 100 (as its % abundance)