Which element has this electron configuration? astatine bromine chlorine fluorine

If i make a solution by adding 83grams of sodium hydroxide to 750ml i’d water what is the molarity of sodium hydroxide

Describe at least two advantages and two disadvantages of using hydropower as a source of energy.

Aweight lifter raises a 1600 n barbell to a height of 2.0 meters. how much work was done? w = fd a) 30 joules b) 3000 joules c) 320 joules d) 3200 joules