Answer 19.9g. I’ve took the test last week at my uncle randy’s house
Mendeleev arranged the elements according to their atomic masses
Answer: C2H2
Explanation: Because each of the lines represent one bond, and because there are three lines (bonds) between the carbons, it means that they are bonded by three bonds, also known as a triple bond.
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 :)