1 )Describe and explain the trends in melting and boiling point for the Group 7 elements

2) Write word equations for the reactions of three group 7 elements with iron. Describe how the vigour of these reactions changes from top to botton of the group.

1.)Trends. The boiling and melting points increase as you go down the group. This is because the strength of the Van Der Waals forces (or induced dipole-dipole interactions) increases since the atoms have more electrons as you descend the group. ... Volatility decreases down the group as the boiling points increase.

answer: c.

explanation:

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.