Which of the following is an effect of the electric force? A. Two negative charges are attracted to one another.
B. Two south poles are attracted to one another.
C. Two north poles repel each other.
D. Two positive charges repel each other.

please help me :(((

Liquid ammonia is produced at high temperatures and under great pressure in a tank by passing a mixture of nitrogen gas and hydrogen gas over an iron catalyst. the reaction is represented by the following equation. n2(g) + 3h2(g) → 2nh3(g) changing all but one experimental condition will affect the amount of ammonia produced. that condition is a) increasing the concentration of both reactants b) changing the temperature within the tank c) decreasing the pressure within the tank. d) increasing only the amount of nitrogen present.

Which of the following is in the lanthanide family? a) uranium b) promethium c) silver d) gold

How many liters of oxygen gas, at standardtemperature and pressure, will react with 35.8 grams ofiron metal? 4 fe (s) + 3 o2 (g) → 2 fe2o3 (s)