B. sodium chloride changed the least; potassium nitrate changed the most.<span />
Answer:
Because the kind of compounds that you try to determine using paper chromatography (organic compounds) are usually not soluble in water. Furthermore, water could react chemically with some of this compounds, because it's a very reactive molecule. You need organic solvents that are mostly inert.
The answer is the last option. Electronegativity is the measure of the attraction that an atom has for electrons involved in chemical bonds. It relates to covalent bonds where electrons are shared. The Pauling scale is the most used.
12.electrons
13.13
14.aluminum has 14 neutron.
B. The sand increases friction by increasing roughness.
