21.69mL - 20.70mL = .99mL Fe
7.8 g / .99 mL = 7.9g/mL
German scientist Döbereiner was one responsible for grouping elements into triads based on most notably atomic mass, many of which can be found in the periodic table to be in a pattern (for example <span><span>Iron </span><span>Cobalt </span><span>Nickel, elements 26, 27, 28)</span></span>
Answer:
48
Explanation:
because you add 6 and 6 and 12 to get it
Magnesium and I think its MG12 for the other part
