Which condition must be met in order for an equation to be balanced? The elements in the reactants are the same as the elements in the products.
There are fewer elements in the reactants than there are in the products.
The rumber of atoms in the reactants is greater than the number of atoms in the products.
The number of atoms in the reactants equals the number of atoms in the products.

D. The number of atoms in the reactants equals the number of atoms in the products.

Explanation:

A chemical equation can be defined as a reaction between two chemical elements.

The condition which must be met in order for an equation to be balanced is that, the number of atoms in the reactants equals the number of atoms in the products.

This ultimately implies that, the mass and charge of the chemical equation are both balanced properly.

ek = (m·v2) / 2

v - velocity of system after the collision

m = m1 + m2

ek = (m1 + m2) ·v2/2

ek = (200 + 250) ·2,32/2 = 450·5,29/2 = 1190,25 j