What is the function of these organelles?

1. combine iron and copper (ii) sulfate solution. (hint: iron will form the iron (iii) ion) fe + cuso4 → 2. combine lead (ii) nitrate and potassium iodide solutions. pb(no3)2+ kl → 3. combine magnesium metal and hydrochloric acid solution. mg + hcl → 4. electrolysis (splitting) of water. h2o → 5. burning magnesium. mg + o2 →

Which element has the lowest electronegativity? calcium(ca) gallium(ga) selenium(se) bromine(br)

Ab c or d ? i’m not sure what the answer is