What is the difference between elements with 13 protons and 13 neutrons and elements with 14 protons and 13 neutrons ?

Is this a single replacement reaction or there is no

What stress will shift the following equilibrium system to the left? n2(g) + 3h2(g) ⇌ 2nh3(g) adding more n2(g) adding more nh3(g) increasing the pressure of the system reducing the volume of the container

If you add 10ml of hot water to 10ml of cold water and the change in tempature 8°c calculate how much energy is gained by the cold water