How do i balance this
Na + Cl² =NaCl

You have to have the same number of each element on left as on the right. You have 2Cl on the left, so you must also have two on the right. When adding numbers to make the equation balanced you can only insert coefficients(numbers that are in front of the the element), not subscripts (the ones that float above). So add a coefficient of 2 to the right so that you have 2Cl. Notice there is no sign between the Na and CL on the right. So when adding the coefficient it goes in front of both of them, looking like 2NaCl. I have 2CL on the right and on the left. Adding the two to the right made there be 2 Na, add 2 to the left to make two Na. It looks like: 2Na+ Cl^2= 2NaCl. You know you’re done because it’s balanced, meaning there’s the same number of each on both sides of the equation.

500bc indiais the answer.