Why does tying the arm above the elbow make veins in the forearm more visible?

It slightly cuts off blood circulation. So your veins begin to bulge at the force of it trying to slip by the tight bond. That's why it sometimes hurts. There is also a better way of wording it, but this is the easiest.

No because it not possibly

Product should she record in last row of the table

rosa was looking for patterns to predict the products of chemical reactions. she recorded three similar decomposition reactions in the table.she should record 2licl + 3o2.

in the last row of the table. it is the thermal decomposition of chlorate lithium, hence, she should record these products as: lithium chloride ( 2licl ) and oxygen ( 3o2 )   2 > 2 licl + 3o2.