Why do scientists measure and record the mass of objects rather than their weight?

Provide a stepwise curved arrow mechanism that fully explains the outcome of the reaction shown below. oh нао* heat он

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space

Classify this reaction: 2al+n2-> aln.