How do i balance chemistry equations?

Let's start with Na^+ + Cl^- --> NaCl

If you look at the Na, and the Cl, you should take into account the invisible number beside them.

1 Na + 1 Cl --> 1 NaCl

note that 1 NaCl means there is 1 Na and 1 Cl

So if you look at both sides, there is 1 Na and 1 Cl on the left, and 1 Na and 1 Cl on the right-- which means it's already balanced

But let's look at this equation

N2 + H2 --> NH3

How many Ns are there on the left? 2 N

How many Hs are there on the left? 2 H

How many Ns are there on the right? 1 N

How many Hs are there on the right? 3 H

so it is not balanced

to make it balanced, we can only add numbers BESIDE the LEFT compounds...

Like this: N2 + 3H2 --> 2NH3

Now look at the left, how many Ns do we have? 2 Ns

Look at the left, how many Hs do we have? 3*2= 6 Hs

Look at the right how many Ns do we have? 2 Ns

Look at the right how many Hs do we have? 2*3= 6 Hs

so as you can see, on the left, our Ns are equal, and on the right our Hs are equal and it is balanced!

Those are different gas lawshere is a brief description of themcharles's law states that volume and temperature are directly proportional to each other as long as pressure is held constant.  boyle's law asserts that pressure and volume are inversely proportional to each other at fixed temperature.gay-lussac's law introduces a direct proportionality between temperature and pressure as long as it is at a constant volume.    source: