Answer:
Ba has the largest atom size
An atoms consists of protons, electrons and neutrons. Protons are positively charged while electrons are negatively charged. Both are electrically attracted to each other. Meanwhile, the neutrons are electrically neutral which do not have a charge. This means that neutrons are neither electrically attracted to the protons nor electrons,
It's been a while... but I'm <em>pretty</em> sure it's
H₂O₄
