That's the commutative property.
I don't know which of these are 'first', but there is the:Identity Property - you can add zero and get the same number back.Commutative Property - numbers can be added in any order and get the same result.Associative Property - numbers can be grouped in parenthesis and added without changing the resulting sum.
Distributive Property: distribute base number, Commutative Property: changing order doesn't change answer, Associative Property: changing gouping doesn't change answer, Identity Property of Addition: any number plus zero equals that number, Identity Property of Multiplication: any number multiplied by one equals that nuber, Zero Property: any number multiplied by zero equals zero
Changing the number of electrons simply makes the atom into an ion without changing the element. Changing the number of neutrons only changes the isotope.
the mass number
subtraction * * * * * The pattern is changing the sign of the number.
Mobile Number Portability (MNP) is a service that allows you to join any of your preferred mobile service provider, without changing your mobile number that you've been using since long.
It means that in an equation, you can multiply both sides (left and right of the equal sign) by the same number (except zero), without changing the result set.