Which statement about elements is true? All substances are made up of elements.
There are approximately 50 elements.
An element is made up of different types of atoms.
Most elements are nonmetal.


first one is right.

there are 117 elements, so 2nd option is wrong.

elements are made up of one type of atoms, so 3rd is also wrong.

most elements are metal. so 3rd is wrong

chemical properties are the characteristic of matter which can only be observed by changing the chemical identity of a sample like flammability reactivity and toxicity.