Answer is #4 (neutrons)
Explanation:
Total mass before the reaction is 236 amu. The total mass of the two elements is 233 amu. This means that there are 3 amus carried by element X. Looking at the total atomic number of the two elements after reaction, it's 92, the same as the one at the beginning. This means that element X has zero atomic number, which could only be a neutron.
Here N H 4 O H { NH }_{ 4 }OH NH4OH is not a strong electrolyte because it doesn't dissociates completely.
Well, you don't need enzymes (biological catalysts) if you're willing to wait a century or two to digest a burger.
Without catalysts, complex reactions like digestion would take too long and the organism could not extract energy from the nutrients it eats in a practical time frame.
In addition, speed is everything in the biological world.
Some reactions and their speed relative to other organisms reactions determines who survives and who doesn't, among other aspects of life.
If a plant is slow to photosynthesize and grow in a habitat high in competition for sunlight real estate, other autotrophs will surely take over.
When a man travels from earth to space, the mass of the person, defined as the amount energy a matter has remains constant. However, when he moves to space, gravity decreases until such time that there is no gravity that acts on the person. Weight thus changes or decreases until the point of state called weightlessness.