Answer:
A is the answer; 'more-efficient extraction techniques
Explanation:
I just took the test and got it right :D
Missing question: Z:X = 7:1 A:Z = 2.5:1 A:Z = 2.2:1 Y:X = 11:1.
Answer is:<span> Z:X = 7:1 and Y:X = 11:1.
Law of multiple proportions or Dalton's Law
said that the ratios of the masses of the second element which
combine with a fixed mass of the first element will be ratios of small whole
numbers.
In this example ratios are whole numbers, A:Z = 2.5 : 1
and A:Z = 2.2 : 1 are not whole number ratios.</span>
6 Atoms!
Mg = 1 atom.
O = 4 atoms.
A = 1 atom.