True
These are all indicators of a chemical change.
Answer:
adjusting the air mix by rotating the barrel and adjusting the gas with the needle valve to obtain a flame of suitable height and intensity
Answer:

Explanation:
magnesium + nitrogen ⟶ Product
13 g 5 g
Mass of product = 13 g + 5 g = 18 g
The product contains 5 g of nitrogen
.
