Arrange the following elements in order of increasing from smallest to largest atomic size K, O, Cs, Se explain why the reason why the trend exist.

smallest is O then Se then K then Cs.

Explanation:

These trends exist. elements tend to get smaller as it completes it's shell since there is more attraction when it is complete. plus the further down the periodic table you go the bigger it is. there are more electrons which repulse each other and make it bigger.

b. examine and describe cells