A pure element is a pure substance that has only one kind of atoms. If a substance is present in nature in elemental form, it means that the element is not very reactive as reactive elements exist in the form of their compounds with atoms of other elements. Element can be categorized as a metal or a non-metal based on some physical observable properties. Generally, metals are shiny lustrous solids and nonmetals are gases. Metals are good conductors of heat and electricity whereas nonmetals are not conductors.
The correct option is Moseley who has discovered the atomic number.
<em>Explanation:</em>
In 1913, H. Moseley discovered a new properties of an element atomic number. He observed that elements in the periodic table can be arranged better according to atomic number rather than atomic mass.
The atomic number of any elements is always equal to numbers of electrons in it.
The type of digestion taking place within the stomach is chemical digestion. When food reacts with stomach acids and other enzymes, a reaction takes place which reduces the food into simpler bits.
The stomach contains strong digestive acids.
Cells in the stomach secrete hydrochloric acid to further aid the digestion of the food.
This way, complex organic molecules becomes broken down into simpler units.
