14. Susan made a dry mixture of pebbles, flour, and epsom salts. She added 50 ml of water to the
mixture. She wants to separate the materials in this
order: first pebbles, second flour, and last epsom
salts. What order is the best way to do this?
a. Evaporation, filtering, screening
b. Screening, filtering, evaporation
c. Filtering, screening, evaporation
d. Evaporation, screening, filtering

Iam not going to tell you

Ineed a picture or something 

Answerreleasing energy.;

Answer: 1s²  2s²  2p⁶explanation: from the periodic table, we can note that the neutral fluorine  has 9 electrons (symbol is shown in the attached image)therefore, the configuration of neutral fluorine  is: 1s²  2s²  2p⁵now, f⁻  means that the neutral fluorine  gained one extra electron. this means that f⁻  has 10 electrons.the extra electron will occupy the 2p level to make it complete.the configuration now  is: 1s²  2s²  2p⁶comparing between both f and f⁻, we can note that f⁻  has now complete orbitals which means that it is more stable than f based on lewis postulatehope this : )