Answer:
D: Chlorine( I may be wrong my chemistry year was a nightmare)
The volume of oxygen produced can be measured using the gas syringe method. The gas collects in the syringe, pushing out against the plunger. The volume of gas that has been produced can be read from the markings on the syringe.
We can define atomic mass the total of number of protons and number of neutrons in an atom or isotope.
<span>So when an isotope of yttrium has 39 protons and 59 neutrons, its atomic mass is equal to;
number of protons + number of neutrons = 39 + 59 = 98</span>
