The difference is intensity is assessed using a special scale and magnitude is measure of the size ( for example a earthquake)
The correct answer is an ''electric current''.
Elements is the simplest form of a pure substance.They cannot be broken down into any thing else ,by either physical or chemical means.In contrasts compounds are pure substances like elements ,they are made up of two or more elements.Just like elements they can be broken down into simpler substances by chemical means,but unlike elements they can only be broken down by chemical means .not both physical and chemical means like elements can.
(I hope that this was helpful.)
