The vertical columns on the periodic table are called groups or families<span> because of their similar chemical behavior. All the members of a </span>family<span> of </span>elements<span> have the</span>same<span> number of valence electrons and similar chemical properties</span>
Answer:
Compound
Explanation:
compound: Substance that is made up of more than one type of atom bonded together
mixture: a combination of two or more elements of compound which are not chemically bonded
Answer:
Covalent bond between identical atoms
Covalent bonds occur between identical atoms or between different atoms whose difference in electronegativity is insufficient to allow transfer of electrons to form ions. ... The two hydrogen atoms are attracted to the same pair of electrons in the covalent bond.