2NH3 (g) + 3Mg (s) — 3H2 (g) + Mg3N2 (s) is a balanced equation.
EEE
O
A. True
O
B. False

True

Explanation:

The equation in this problem is:

where:

N is nitrogen

H is hydrogen

Mg is magnesium

(s) represents an element/compound in solid state

(g) represents an element/compound in gaseous state

A chemical equation is said to be balanced if the number of atoms of each element is equal on the right and on the left of the equation.

Let's verify it for this equation:

Nitrogen:

We have 2 atoms on the left and 2 atoms on the right -> balanced

Hydrogen:

we have 2*3=6 atoms on the left and 3*2=6 atoms on the right -> balanced

Magnesium:

we have 3 atoms on the left and 3 atoms on the right -> balanced

Therefore, the equation is balanced

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s