Name an element in the same period as rubidium

Potassium(K)

Explanation:

its an alkali metal placed under sodium and its over rubidium, its also the first element of period 4

28. evolution

29. environment, survive, offspring  

explanation:

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.