The scientific meaning of salt is an ionic compound that is formed when an acid and a base reaction take place and is neutralized.
The common meaning of salt (table salt) is specifically the organic mineral of sodium chloride (NaCl) and is digestible.
Ionic salts are often not digestible (or not commonly digested, anyway)
That would be the proton. The number of protons in the nucleus determine which element it is and its properties.
Answer:
1. S+ O2-->So2..... synthesis reaction or direct combination.
2.. precipitation reaction
3. Displacement reaction
4. Decomposition reaction
Your instructor is probably expecting the answer B) III only.
III) The evolution or <em>absorption of heat</em> is evidence of a <em>chemical change</em>.
I) Boiling water and IV) mixing paint are <em>physical changes</em>.
II) A change in colour on mixing is usually an indication of a reaction (but not when mixing paint). However, in this case, the lighter blue colour might have happened simply because you are diluting the solution. You would have to do an experiment which is correct.
