Answer:
was difficult to place isotopes of elements as they have the same chemical properties but different atomic masses. It was not possible to predict how many elements could be discovered between two heavy elements as the rise in atomic mass is not uniform.
Answer:
hydrant flying with balloon, balloon has lithp letting air out, bee: really yum balloon
= = = =
hydrogen helium lithium beryllium
be bore on the balloon, balloon pops, hydrant drops and makes a car bomb
= =
boron carbon
night row general gets hurt by car bomb nearby, that general gets off boat
=
nitrogen
wearing oxygen mask, mask is full of fluride gel, then he got neon teeth
= = =
oxygen fluorine neon
(try making a story out of the elements, use your imagenation)
Covalent since they are both non metals, a metal and a non metal make an ionic bond
