Answer:A
Explanation:
The melting points of solids depend in the relative sizes of ions in the ionic lattice. The smaller the relative sizes of the ions, the higher the lattice energy and the stronger the lattice hence higher melting point. Comparing relative ionic sizes, fluoride ion is lesser in size than chloride ion hence NaF has a higher melting point than NaCl.
The study of plants, plant life cycles, photosynthesis, plant parts, etc. is under botany (study of plants).
Answer: 34.4 g
Explanation:


As
is in excess,
is the limiting reagent and thus it will limit the formation of products.

According to stoichiometry:
2 moles of hydrogen produce = 1 mole of 
2.5 moles of hydrogen produce =
of 
Mass of 
But as % yield is 86%, mass of
produded is 
Thus 34.4 g of
is produced.