BODMAS=Bracket, Order, Division, Multiplication, Addition and Subtraction. In certain regions, PEMDAS (Parentheses, Exponents, Multiplication, Division, Addition and Subtraction) is the synonym of BODMAS. It explains the order of operations to solve an expression.
zinc will react with sulphuric acid forming zinc sulphate dissolved in solution and releasing hydrogen gas.
Zn + conc. 2 H2SO4 ZnSO4 + SO2 + 2 H2O
The order of magnitude of a physical quantity is its magnitude in powers of ten when the physical quantity is expressed in powers of ten with one digit to the left of the decimal.
Orders of magnitude are generally used to make very approximate comparisons and reflect very large differences.

Great my son!
You've been truly inspiration, dai! Congratulations to you and all of us.