Reactivity of Group 1 and 2 elements increases as you go down the periodic table. So sodium is more reactive than lithium. Sodium will react with oxygen forming Na2O (sodium oxide). Lithium forms lithium oxide (Li2O).
Such an object makes a larger dent in the fabric of space-time than an object with little mass. (It has a greater gravitational attraction than less massive objects)
A greater force is required to accelerate such an object than a less massive object
∆H = m x s x ∆T, where m is the mass of the reactants, s is the specific heat of the product, and ∆T is the change in temperature from the reaction.