Is mercury a heavier element than tin

Which element has the lowest electronegativity? calcium(ca) gallium(ga) selenium(se) bromine(br)

Which of the following are good traits of a hypothesis? it will be able to be testedit can predict an outcomeit will explain the observationsall of these

How does the atmosphere to make earth livable? check all that apply. causes the seasons contains oxygen provides warmth creates important nutrients blocks harmful energy from the sun plz like !