All matter is made up of particles called atoms and molecules (as opposed to being continuous or just including particles). On the following page, the idea is stated as one of four concepts in Dalton's theory: “All matter is composed of tiny, indivisible particles called atoms” (p. 158s).
Answer: Ionic radii is half the distance between two ions.
Explanation: from top to bottom down an element group, ionic radius increases. This is because a new electron shell is added as you move down the periodic table.
Might Be wrong not sure :)
Answer:
Ne
Explanation:
Noble gas, Unreactive therefore does not exist as a diatomic molecule